My main is a level 55 warlock. I've found this strat to be fast and simple.

With Corruption rank 6, Siphon Life rank 3, and CoA rank 5 you can do this strat without ever stopping.

Here it is. Goto Kargath (Badlands) and just outside the horde FP are the level 37-38 rock elementals.
Now I know everyone knows about this place, but they may NOT know that the 3 above mentioned dots
will kill one of those ele's without another hit. So what you do is run through triple dotting 6-7 at a time and then
just wait for them to die while you regen your mana. I managed to do the entire camp of these elementals in
less than 5 minutes for a total of a little more than 2 gold from the rock drops. This seems to be fairly consistent
across runs. So there you have it … 1-2g every 5 mins or so is a pretty decent VERY low risk way to make cash.