4 WoW Warlock Gold Farming Tips to Make You More Gold
1. Spec for Affliction
If you want to grind gold, the Affliction spec is probably the most useful. You can take out plenty of mobs and your downtime is significantly reduced which means that you can grind faster. Between instant casts and the excellent mana efficiency, you'll be a grinding machine.
2. Find some good Warlock gold farming spots
Once your Lock finds a good spot to farm gold, exploit the hell out of it. Some places that are particularly lucrative are Legion Hold; Skettis (farming Primal Water); Mana Forges in Netherstorm (for scryer rep); and you can farm Brilliants in Stratholme. Oh, and don't forget Shadowmoon Valley. The Black Temple is a good spot there for all sorts of stuff that gets good prices in the Auction House - you can pick up cash, vendor trash and some decent rare drops.
If you happen to be on a PvP server, you can farm primals on Elemental Plateau, but you sure won't be alone there so it's up to you whether it's worth your time. Personally I'd rather just concentrate on leveling to 80 asap and then start doing dailies as you hit level 70. It's much easier that way.
3. Do your Dailies
Once you reach level 70, making gold couldn't be easier. Just do the daily quests that are available. Best dailies for Warlocks are in Isle of Quel'danas. You should make pretty good bank there just be logging in daily to run a bunch of these short, easy quests. If you're a casual player, you should still be able to manage about 10 dailies in just about an hour.
4. Level an Alt
I'm sure you already know about having an Alt that can hang out by the Auction House. But if you really want to make heaps of gold, I think it's a good idea to level another character that is great at gold farming. I recommend a Hunter, as it is an easy solo leveler as well. For tips on leveling a hunter fast, check out the hunter leveling guide.
These tips should get your Warlock going pretty well, but if you really want to learn the best gold making methods so you can get as much gold as possible, then I recommend Luke Brown's WoW Gold Secrets Guide. He has tons of strategies for making more gold at every level, for every character class, including the Warlock.

