I agree with the posts that say learn some vanishes etc, however these take time an I'm assuming you want to fool people TODAY!!
The extra layer already advised by Tomsk will help.
Where are you vanishing it from when doing it? From the back of a spectators hand or your own hands?
If it's in your own hands then one suggestion is get them closer together on the pass, when i do the key bend from the X2 model i brush my hands together, this can be done very quick after a bit of practice?
After a while using it you get a feel for it and know how high/low to have it.
Hope this helps,
Sam.