Ok, heres what I do. You basically sell an item, for a higher price.
You Need:
Good item switching skills
2X Copy of 1 item (i know it's a stretch)
Enchanting mat's for given enchantment (I.e Mongoose, +15 agi etc)
A Noob!
The Method:
1. Get 2 of a highly prized weapon (Points for weapon, farmable and good for twinks) I.E Assassin's Blade - Items - World of Warcraft (Assassin's Blade)
2. Slap a suitable enchant on it (i did a relatively cheap and effective one, Fiery that way the loss isn't too much)
3. Now, on my server, it's worth 80g~ and the enchant mats are 30g~, so I put it on and advertised it for 100g, got it up to 120g from /2 bid's.
4. I met the guy in SW
5. He opened a trade, popped the 120g in I put the fiery one in
6. in a quick motion i put the non enchanted one in and win
7. ???????
8. Profit (well actually i do know)
I have done this and made Poop loads from it Enjoy
(PS. I do not want rep, i have made this. but its not worthy of a cookie)