Everything is rock bottom cheap at the moment because everyone is leveling and everyone has gathering professions. Most profession mats are selling for barely above vendor price on the AH. Enchanting mats are basically worthless because nobody yet has any good enchanting recipes (and the demand for top end enchanting recipes is what drives demand for the entire profession, since hardly anybody bothers to enchant gear while leveling).
I have almost all of my profits by simply crafting things and vendoring, taking advantage of the ridiculously low prices of ores, stone, leather and cloth. Engineering is very good for this (explosives vendor really well).
There are a lot of profitable crafts out there right now - especially cooking. Roast Raptor, Curiously Tasty Omelet, Carrion Surprise are all vendoring for a profit on my server.