With the slew of new levelers, both now with new class and race combinations and next week with goblins and worgen, there will be a unique opportunity out there. I am talking about recipes, specifically recipes that are world drops. If you fanatically collect recipes for no particular reason, like I do, then you know how frustrating it can be to collect those low level green recipes that have a minuscule chance of dropping of any mob in Eastern Kingdoms and Kalimdor, I’m looking at you Lesser Block and Star Belt. But with so many more people leveling, world drop recipes will actually start appearing on the Auction House. In fact I recently acquired the Shadow Hood pattern for 1 gold, I would have paid thousands.
Collectors like me should always be on the lookout. Check the Usable box and search the recipe section often. You might even want to advertise in trade that you will pay for any recipe you don’t have and link your tradeskill, although this may cause you to pay more because you have tipped them off that these are of some value, at least to you.
Familiarize yourself with what recipes are world drops. Either add them to you snatch list or take a look at Ackis Recipe List mentioned below. Most world drops you find will be posted for a pittance by people who don’t know what they are worth. You can flip this for a nice profit, although only to collectors so it might take a bit to find a buyer.
If you aren’t looking to collect yourself or profit off of others collective tendencies the one thing you should do is do your research. If you happen upon a recipe take a minute and look it up so that you know what you’ve got. I do a literal face palm when I think about all of the things I vendored when I was but a nub, don't make the mistake of throwing these potentially valuable recipes away.
I've raved about this addon before, but I'll mention it again. This great addon will give you a menu of all the recipes you don't know and where to get it. Even if you are not a collector you can use it to determine what recipes are world drops.