Haven't found another post of this one so here we go. It isn't much but easy gold if you aren't 70 yet (or higher).
Go to Haalrun - NPC - World of Warcraft
Buy the recipes and put them on AH (especially the Recipe: Super Mana Potion)). On my server I already sold 5 in a week for +/- 30g (total 150g). I have a AH char (just like the rest) so I just drop by, buy it, send it and do the next day the same thing.