Produce a 36-inch scarf and cover the kid? Stick a pacifier with a balloon on it in his/her mouth?

I also do the spong balls. when I finish depending on how old the child is I ask them to hold a an invisable ball really tight. Then do a couple more tricks for the sdults then at the end ask the child if they felt anything happen. when they say no, tell them to open their hand and shout wow, you made it dissapear.