Firstly, you can obviously farm instances such as BRD for Large Brilliant Shards. These sell for about 6-8g currenly on my server.

This post will detail a large part of making wow gold by disenchanting items from crafting.
Lets presume you either have a friend who can make and disenchant for you, or you have all the characters and patterns you need to do all this yourself.
Note that it "really" helps here if you can do this all by yourself, as you won't have to share your profits.

This method involves the combination of trade crafts, and disenchanting the results.
We'll aim at the popular high end enchanting materials.