Well here we go, once again!!!
What you need: Lots of one item!!
Now all you have to do is go to the auction house when theres none of your item that you have a lot of on (lets say you have 150 silk cloth) You post it all (maybe even a little over priced) Now, think of a blue item or epic worth near the cost of the silk (hopefully more but not to much to make it believeable, such as trade and then they sell for 5-15g more) Now all you do in the trade channel is say something like
WTT (item you have bulk of) for (the linked blue from AH)
(lets say you have 150 silk cloth and they are going 1g each and face smasher is about 10g, reasonable right?)
WTT Face Smasher for 120xSilk Cloth.
Easy sounds good to me, now all this does is make people buy the silk off the AH and trade it attempt to message you saying they have 120 silk cloth and to trade it, just go AFK, DND, or Log out for 10-15 min or say you already traded it.
Hints and Tips: Instead of saying all 150 silk cloth you should say 100-120 TOPS due to the fact more then 1 person might go AH it to see if cheap Silk is on, or if its a good deal, also dont make the blue to expensive over the item because it will make it less believable.
As far as I know this is in no way bannable or even suspenable enjoy! ^.^