Farming gold as a goal is not really necessary as a warlock until you advance past 60 and want your epic mount. Our mount at 40 is free. By simply progressing through quests or grinding you will steadily increase your gold surplus, unless you blow it all at the auction house. However, you can improve the gold you gather while levelling greatly by picking up a profession from the start. Check the next paragraph for info on that. When deciding whether to buy that shiny new robe in the auction house, especially if you’re at a lower level, think twice. Chances are you will either receive a similar or better robe through a quest or drop, or outgrow the robe you buy in a few levels, making you wish you had never spent the gold on it. The main thing you really should consider spending some money on while levelling should be bigger bags, as those are always nice to have, and retain their value through the levels. (Never buy bags from the NPC bag vendors except maybe some 6 slotters early on, the rest are far too overpriced compared to the bags you will find in the auction house).
Professions
An easy way to make extra gold is to pick up gathering professions, as they are easy to do on the side while levelling. Skinning, Herbalism and Mining work perfectly, and provide a steady influx of gold. Enchanting is not a good moneymaker while you level it up, you won't easily making a decent profit until you get to the higher level enchants.
You could fill up both your profession choices with gathering skills for extra profit. Keep in mind that you will not be able to craft anything if you go with two gathering professions. You will only be able to sell what you collect, so this is not recommended if you want to be able to create anything. Crafting professions would seem appealing for making some gold as well, but most of them require you to put in cash for vendor bought ingredients. In general, you will make more money selling the ingredients than you will after combining them into finished products. Exceptions are Alchemy and Jewelcrafting. Taken alongside Herbalism and Mining respectively, you will be able to produce items that do quite well in the auction house.

Farming
A good way I’ve found to gather gold, is to find an area with humanoids that are equal or a little below your level, and go on a killing spree. Collect everything they drop. Once your inventory is full, sell the grey items, place the good things like cloth and green or better items with nice stats in the auction house, and resume killing. Doing that for a few hours should net you a good amount of gold. Element of importance here is your talent spec. Affliction and Demo specs are quite well suited towards farming while Destro has a hard time to keep going without downtime.
Enemies that yield good drops, plus some generic info
It is worth noting that some grey items sell for a very low amount, while others provide a good deal of money. For level 50+, try some of the following;
-An example would be Gorillas in Un’goro crater. Ranging from level 47-53 they drop tufts of hair selling for 11 silver, and empty barrels (Donkey Kong reference ;) selling for 15 silver a piece. They are located by a cave in the northeast with thorium and truesilver deposits, should you be a miner. The plaguebats in Eastern Plaguelands also drop some very well selling stuff, such as Bat ears (8s each), Large bat fangs (16s each) and Sleek Bat Pelts (12s each). They also drop Evil Bat Eyes, which are used as a turning for Darkmoon Faire Cards.
-A good monster type is earth elementals. The things they drop aren’t worth that much on their own, but they drop a lot of it, so it ends up worthwhile. Elemental Earth, Core of Earth and Essence of Earth are worth good money in the AH as well.
-Hearts of Fire sell nicely, the best place to get them is off of Entropic Beasts (51-52) in Felwood, north of Bloodvenom Falls.

-Another decent one is killing level ~36 trolls in Stranglethorn Vale and ~40 trolls in The Hinterlands. They drop regular humanoid loot, and have a small chance to drop wildvine which sells quite well in the AH. (On most servers for 1g a piece) The troll sweat they drop sells for only 70 copper each and stacks in 5, so you might not want to bother with that if your inv is filling up. The necklaces they drop in hinterlands sell for the

same, but stack up to 20. They’re worth keeping to sell. The flasks of mojo sells for 2s50c each and stack to 20, so they’re nice too.
-Felcloth sells reasonably well in the AH, as it is used to make mooncloth. Good farm spots are the Satyr in the northernmost Satyr camp in Felwood, and level 51 and higher Legashi Satyr in Azshara.
For level 60+ in outland, there are some much bigger moneymakers to farm;
-Primals rank high as moneymaker, I will list them seperately including camp spots. Check the AH on your server to find out the pricing on them and decide which you want to farm. The percentage figures points out the droprate for the specific location.
Primal Air
-Shadowmoon Valley: (25.7%) 69-70 Enraged Air Spirits in the Southeast and Northeast by the edges of Shadowmoon Valley. The Southeastern spot is most favorable but highly camped. Use the northeastern location as an alternative.
-Nagrand: (34%) 70-71 Storming Wind-Rippers on the Elemental Plateau, northeast of the Throne of Elements which requires a flying mount to reach. The Elemental Plateau is heavily farmed as well. These air elementals are in low hitpoints mobs, and not especially damaging. (dont stand in the cloudstorms they cast above you)
Primal Fire
-Nagrand: (34%) 70-71 Raging Fire-Souls on the Elemental Plateau.
-Shadowmoon Valley: (25.8%) 68-69 Enraged Fire Spirits west of the hand of Gul'dan in the center of the zone. Some of these are in lava and will shoot you from range, which can be annoying when they die in there. They'll usually run up to you after a nuke or two though.
-Blade's Edge Mountains: (25.7%) Searing Elementals in the northeast of the zone, in an area called Skald. There are some non-fire mote dropping mobs around, basilisks and imps. The basilisks drop items of value themselves though, meat used for +spell damage food.
-Mining: (10%) Fel Iron and Nethercite Deposits.
Primal Water

-Terokkar Forest: (17.8%) 62-63 Shimmerscale Eels in a small lake just northeast of Shattrath. The eels in the lake have a 18% drop chance of motes which isn't very high. However, they only have 3300-3400 hp and are very easily killed. The lake often gets quite full of farmers, but there are other locations;
-Nagrand: (33.8%) 70-71 Crashing Wave-Spirits on the Elemental Plateau.
-Terokkar Forest: (33.9%) 70-71 Skettis Surger. You can find these in the Skettis area, which requires a flying mount to reach.
-Nagrand: (18.9%) 64-65 Lake Spirits in the lake north of Garadar.
-Nagrand: (19%) 65-66 Lake Surgers in the lake by Sunspring Post.
-Shadowmoon Valley: (25.7%) 68-69 Enraged Water Spirit. Not too many of them around, and many non-elemental mobs in the way.
Primal Mana
-Shadowmoon Valley: (25.7%) 68-70 Netherskates south of the crystals fields.
-Shadowmoon Valley (25.8%) 69-70 Netherwing Rays on the edges of Netherwing Ledge. (Requires flying mount)

-Netherstorm: (25.6%) 67-68 Phase Hunters on the northwestern and eastern edges of the island Area 52 is located on. These buggers will manaburn you, which can make them fairly annoying to fight as a non-felguard lock. Nether Rays drop motes of mana as well.
-Netherstorm: (25.6%) 67-68 Mana Wraiths in the glowing trenches south and north of Area 52. These cast a mana drain.
-Netherstorm: (26%) 68-69 Mageslayers and Mana Seekers in Kirin'var Village. Mageslayers occassionally cast a shield that makes them reflect spells, which makes them vey annoying to fight. If you can burn them down really fast (they only have 5.5k hp) you may have enjoy farming these. The Mana Seekers spawn in the same area and aren't as irritating.
Primal Shadow
-Nagrand: (18.7%) 65-66 Voidspawns in the southwest around Ushu'gun. These actually give you a little health regeneration buff after you kill them, which helps with farming them. They have a small healthpool.
-Hellfire Peninsula: (18.7%) 61-62 Vacillating Voidcallers and Collapsing Voidwalkers on the edge of HP east of Zeth'gor. The abilities of these mobs and their relatively high hitpoints (compared to the Nagrand ones) make them a bit of a pain to farm. Vacillating voids gain 75% resistance to spells of the school theyre first hit with. If you open with immolate and proceed with just shadow he will probably switch to 75% shadow resistance later on. The Collpasing voids will explode for 1000-1.500 shadow damage when you kill them. The radius of the explosion is small though.
-Hellfire Peninsula (10.8%) 60-61 Rogue and Ucontrolled Voidwalkers. These have low hitpoints and make for easy kills, but have a low drop rate.
Primal Life
-Zangarmarsh: (18.7%) 61-62 Withered Giants and withered Bog Lords in the Dread Mire northeast in the zone.
-Zangarmarsh: (18.9%) 63-64 Fungal Giants and Bog Lords south of Zabra'Jin.

-Terokkar Forest: (18.8%) 64-65 Infested Root Walkers and the occasional Rotting Forest Rager. Find them all along the border of the Bone Wastes.
-Herbalism: (~15%) from Mana Thistle, Dreaming Glory, Felweed, Ragveil, Terocone and Ancient lichen. (8-9%) when herbing dead fungal giants.
Primal Earth
-Netherstorm: (19.8%) 68-69 Sundered Thunderers northwest of Stormspire.
-Netherstorm: (18.7%) 67-68 Sundered Rumblers south of Area 52.
-Nagrand: (18.6%) 66-67 Shattered Rumblers on the southern edges of the zone. When they die, little earth elementals spawn. If you and your pet are far enough away when it happens, the little guys wont aggro.
-Shadowmoon Valley: (18.3%) 68-69 Enraged Earth Spirits. These are in the same area as the fire elementals, west of the Hand of Gul'dan.
-Mining: 19.8% for Adamantite, Rich Adamantite and Khorium. Fel Iron and Nethercite (Netherwing reputation ore) have a 10% chance.
Next up are Fel Armaments, Arcane Tomes, Marks and Signets. These items provide reputation increases for the Scryer and Aldor reps in Shattrath, they sell well.
Firewing Signet and Arcane Tome
-Terokkar Forest: (33.4%) 64-64 Firewing mobs, found exclusively in Firewing Village in the northeast of the zone. The mobs make for easy kills, and the area is generally quite popular wirth scryers working their rep and farmers in general.
Sunfury Signet and Arcane Tome
-Shadowmoon Valley: (~28%) 68-70 Eclipsion mobs south of the Hand of Gul'dan. You can them on the Path of Conquest in groups of 2-3, but you can also find them in single pull variety a bit to the west in Eclipse point.
-Shadowmoon Valley: (~28%) 67-70 Sunfuries and Demon Hunters in the southern wing of the Black Temple.
-Netherstorm: (~28%) 67-70 Sunfuries around Mana Forge B'naar, Coruu and Duro. I wouldnt bother with Manaforge Ara as the mobs there suck to kill in comparison to the others. Manaforge Ultris has no Sunfury mobs by it.
Mark of Kil'Jaeden and Fel Armament

-Nagrand: (33.1%) 66-68 Gan'arg Tinkerers in the Forge Bases to the west. Try enslaving a Felguard Legionnaire elite for some very speedy killing.
-Terokkar Forest: (33.4%) 62-64 Cabalists south and west of the Refuge Caravan.
-Nagrand: (~33%) 65-67 Kil'sorrows in Kil'sorrow Fortress in the Southeast.
Mark of Sageras and Fel Armament
-Blade's Edge Mountains: (~27.5%) 67-68 Demons in Death's Door, west of Mok'Nathal village. Especially the Deathforge Technicians make for easy kills.
-Shadowmoon Valley: (~28%) 66-68 Demons in Legion Hold, in the west of the zone.
-Shadowmoon Valley: (~28%) 68-69 Deathforge mobs in the Deathforge, just west of the Hand of Gul'dan.
-Netherstorm (~28%) 67-70 demons in the general northwest area. There are two forge bases, a tiny island off the 'coast' and you will find demons in and below Manaforge Ara. I don't really like the Forge bases as the Fel cannons are kind of a nuisance, but the mine and the tiny island aren't bad.
-Netherstorm: (~28%) 67-68 Artifact Seekers and Felblade Doomguards. The Artifact Seekers can silence and manaburn you, but they dont have much hp.
Some green items, even with nice stats, are difficult to sell at the AH. This is usually because there is a quest with an item of that type, in that level range, as a reward. It’s sometimes hard to tell what sells well and what doesn’t, because of that.
The best tip I can give is to do a search on the item you are about to place up for auction. If there are a lot of auctions for that item, chances are it doesn’t sell too easily and you can consider selling it to an NPC merchant instead. You should always do a search when putting items up at the AH anyway, because the default recommended price is usually off.
Daily Quests
Another good way to make some gold is by completing daily quests. These quests are available at level 70 and provide you around 12g on a quest turnin. Daily quests can be gotten in Ogri'la in Blade's Edge, by the

Skyguard near Skettis in Terokkar. You can also do Netherwing dailies provided you've completed the 'Kindness' questline and own an epic flying mount.
Instance Runs
Another option for collecting gold is to form or join a group and do some instance runs. Mobs in instances tend to be much more generous with item and cash drops, and this will help you out nicely. As you level way beyond the level range of an instance, you can do an instance solo. You can often bypass large amounts of enemies because of your reduced aggro range due to the level difference, especially if the enemies are grey to you.
Going this route can be extra valuable to enchanters, who can DE the BoP blues they get and sell them for more than what the vendor would give you for it.
Blackrock Depths
I have not tried this zone for farming yet. It may be worthwhile especially for enchanters.
Level 70 comes recommended, soloing the instance should definately be interesting.
Scarlet Monastery
This instance is no longer worth much to do, as you can get more gold faster in Outland. It may be worthwhile if you are an enchanter in need of shards.
Uldaman
Pretty much the same deal as Scarlet Monastery. Possibly worthwhile for enchanters.
Mauradon
Running this instance is not really worth it anymore past 60. I'm leaving the description in place in case someone is interested in doing it anyway.
Mauradon instance runs: You’re easiest off doing this if you are level 60+, because almost everything in the dungeon will be grey and wont aggro unless you get very close. You have to do the Legend of Maraudon quest (best done grouped) to receive the scepter of Celebras, which allows you to teleport to the end of the dungeon. Once ported inside you can kill Tinkerer Gizlock. Don’t try and kill him in melee range, but hit him up with DoTs from a small distance and use drain life. He will drop one of three blue items selling between 2.4 – 3.2

gold. The dagger he drops has a +14 spell crit rating, you might want to actually use it. Getting from the entrance of the zone to Gizlock and killing him takes all of 5 minutes. However, you can’t just walk up to an exit and re-enter, since you’re deep into the dungeon. The easiest way is to die and run back. (unequip all your items with durability before dying) You could also bind in Shadowprey Village if you are horde, and let yourself get kicked out of the instance when you’ve killed Gizlock. (have someone invite you to a group, and drop when youre done inside. This will port you to your hearth location after a minute). All in all you can expect to take about 15-20 minutes per Gizlock kill. Its not a great moneymaker, but its ok if you want to do something different.
Princess Theradras can also be killed, but i'd recommend waiting til you are a bit above 60 to do it. Getting to her without aggroing the giants guarding both sides of the path leading to her requires you to move exactly through the middle of the path, as well as beng mindful that you don’t let your pet move alongside you and aggro them.
Auctioneering
Let me begin by warning you that Auctioneering can stain your reputation when you take a really aggressive approach whereby you try to control the market on an item or group of items. You could do it with an alt though. It’s not against blizzard’s rules to be a marker controller, but many people don’t like it and may dislike you for it. It isn’t for everyone. It is boring to some, but can be a game in itself. You need a small starter capital to make a smooth start. You could start really small, (as little as a few gold will do), but that will require a little more patience. More gold to start with makes thing easier.
What you do is apply the simple principle of buying low and selling higher.
-To start off, take a trip to the auction house and do a search on a few item types. (For example, Fel Iron and Adamantite Ore / Bars) Note the prices they are being sold for. Do the same in the following few days.
-Once you have an idea what the average prices for a product type are, start buying all of the Mithril and Thorium that is being sold below that price.

-Start auctions for the items you just bought, and put them up at the average price, or a little above that. As long as it ends up being sold, you’re making profit. This requires some experimentation.
-If you get this working, you can expand your business in other product types. Find out what something sells for, buy anything underpriced and sell it off again.
A daily 5-10 minute trip to the auction house can suffice. If you like doing this though, you might end up staying at the AH for hours a day.
Doing this, even going for the one trip a day to the AH, can net you large amounts of gold if done well.