Ok.. So I found this out 1 day by accident.
I was like.. making alot of heavy netherweave bandages and a guy asks for an enchant in trade (Dosnt matter what kind). I whisp him and tell I'll do it for him, and he comes to me.
Nothing special so far..
So.. Here's the trick.
He trades me the materials needed, I open my enchanting window and clicks the enchant to pop on his item as he trades it to me. I put it on the item and it says "Will receive enchant: Brawn" or something similar aye.
Anyhow.. I open my firstaid beside the trade window as enchanting window is closed and the enchant is ready to take place, and I start makin bandages again.
As he adds some tip and presses "trade" I'm casting netherweave bandage aye? So I click trade aswell.
What happends is the enchant isn't applied to the item, but the tips is still given.
This way I tricked a poor noob to give me 150g tip for 12 agility on cloak..
Tried alot of times to replicate, and works every time.
Questions?Send me a msg..