I play on a roleplaying server. Roleplaying servers can be a bit different than you standard server when it comes to making gold.
On roleplaying servers, there seems to be a premium on vanity, and not when it comes to raid gear.
On RP server, things that make a good outfit are highly sought after.
You can sell a lot of these items at a very significant mark up.
What kinds of items am I talking about? Shirts, pants, dresses, hats, and other miscellaneous headgear.
Tops: If you are a tailor, there are quite a few of these that sell well. I find that the ones that sell the best are the Swashbuckler shirts. I dont know if it is the name or what they look like, but they sell of a fairly regular basis. Other fairly popular shirts include the Black Silk Shirt (perhaps because it is black) and Pink Mageweave shirts. One that I have sold for 120-150 gold each are the vendor "shirts" that you buy from the first aid vendor in Dalaran. There is a anticeptic dressing and wound dressing (or something close to that). They look like you took some wounds and are bandaged up. Nice touch depending on what kind of roleplaying you are doing. I also sell the Tuxedo shirt on a fairly regular basis.
Dresses sell on a fairly regular basis as well. The wedding dress and the one of the black dresses sell pretty well. I have also grabbed and sold a few of the Hanbocks from the vendor in Moonglade.
Pants: The only pants I generally sell are the Tuxedo pants. If you sell these, you stand a chance of selling the rest of the set if it is on the auctionhouse.
Head: There are several good options for the head slot. I sell the Admiral's hat for between 25-75 gold. They cost very little to make. Engineering is also a pretty decent profession to make head pieces. You can make a couple of different kinds of goggles which may or may not sell. As a Jewelcrafter, you can make some pretty cool monacles. I have only sold one of the amber ones, but it sold for 1500 gold.
If it looks cool, it can sell....especially on an RP server.