If you are dead set on leveling a production trade skill instead of taking two of the gathering skills, remember that not everything your trainer offers is worth buying. While it might be nice to have a long list of colorful shirts and dresses to produce as a tailor, for instance, the truth is they offer very little in the way of potential revenue. Also keep in mind that, generally, whatever items you craft at lower levels will not likely sell for more money than you could have made by simply selling the raw materials used to make them. For this reason, two gathering skills are highly recommended until you get closer to 80 (70 if you don't have the WotLK expansion or 60 if you don't have the TBC expansion).
This new farm takes advantage of the level scaling changes implemented by blizzard.  Event NPC's like the NPC's found in the twilight outpost, scale up or down depending on your level. HOWEVER, your level also determines which loot tables each mob will have.  By using a level 58 character, you can successfully loot items in the 57 – 59 item range, a range which has some of the most expensive and well sought after transmog items in the game.  In less than 30 minutes farming this spot I was able to snatch up some glorious legplates[/URL] (on video) – worth a stunning 150,000g.  Watch the video for absolute details I suppose, but the gist of it is you need to create a level 58 DK, go to the twilight camps, and start the killin'.  Unlike before, an implementation of a daily event has changed the loot tables!   This spot is the new hot thing on the block.
If i start on a new realms, I am farming a lot of transmog from classic and Burning Crusade Dungeons and Raids. In the beginning, i start to post them if they have at least a DBRegionMarketAvg (Average value of an item on all EU realms of the last 14 days) of 500 Gold. All the other items get vendored. The time you hit a stock of 1000 Items, my value treshold raises to around 2.500 Gold. All the items below that value get vendored aswell. Newly farmed items that are above these treshold will be listed. Why? If I start over somewhere, I want to get a certain amount of gold quickly. Cheap items are great for that. Later on, to save time, Quality is better than quantity. As mentioned above, re-posting the items on the auction house takes quite a bit of time. At this point, I can recommend you the TradeSkillMaster AddOn, it makes your auction house work really a hell of a lot easier.