Find a tall, empty plastic cup. A disposable cup will work well too. The taller the cup, the better the illusion will appear.
Stick a very small piece of wax to the side of the cup. Place your thumb (either hand) in the wax. This should cause the cup to stick to your thumb. This piece of wax should be warm enough to stick to your finger but not so hot that it is running off the cup or burning you.
Push your thumb away from the cup slightly so it is not noticeable that your thumb is actually stuck to the cup in anyway.
Wiggle your thumb and other fingers around the cup. This will give the impression to the audience that the cup is not just levitating but also dancing about at the motion of your hand.
Study ways to make this trick even more personal. Most magicians find ways to improve on their tricks and you should do the same.