One of the best ways to get wow gold is to obviously train for it, meaning you go out and kill enemies and take whatever items and other valuables they may have on them at the time. When you do this, make sure you have a mage with you or someone else who can heal. In a way, it's like old-school console RPGs; you go into the field and kill enemies, not using items to heal yourself but just using magic Cure spells or the like. Items cost wow gold - and the more items you use, the more you have to restock. Also, try to accurately gauge your level.

 

Yes, you could take your level 20 fighter into the level 10 enemies, but there's not really going to be a lot of wow gold from them relative to what you should be getting. Try to fight monsters that are within a few levels of you - maybe two or three in either direction. This is because it takes a lot of time to get any worthy amount of wow gold from low-level enemies.