This is a simple scam, it works 90% of the time (provided there are buyers)
Ever notice the cost of shirts lately? People are willing to pay 1-2g for shirts.
Check your AH, find out if anyone is selling the shirts with the prefix and suffix "Common x Shirt", x being the color.
Head to your local noobies zone. Well, the one after the noobie zone. For Trolls/Orcs this would be the Barrens, for Dwarves it's loch Modan, basically your 12-22 area.
Now go to the major town of this zone. Find the clothier.
He should be selling Yellow, Grey, or perhaps even black shirts.
Buy as many as you want, just enough to ensure you some substantial gold.
Head to the AH and post them for 1g each, but be sure to check if there are any for cheaper before you post.
Tip: Don't flood the AH, people will just realize the true value and undercut you.
Again, try to keep this underground :D
I claim the server Frostmane, horde side! :P