To do this, engineering at level 350 is required. Epic flying mount makes it a lot better, but is not required. Here goes.
First, you need to create http://www.wowhead.com/?item=23821, and http://www.wowhead.com/?item=32461, or any other goggles that allow you to see gas clouds. Then, simply get on your mount, and collect either primal airs in Nagrand (route herehttp://img128.imageshack.us/img128/7741/farmingmotesairco7.png), or shadows in SMV. I prefer airs though, as they usually sell for more. I was getting about 12-15 airs an hour doing this. Note, if you don't have epic flying, you gathering will slow down a lot.
This was hardly a guide, just a little tip, but I hope people can use this, as it definately helped me.
