Place a blue rubber band around the index and middle fingers on your right hand and a green rubber band around your ring and pinky fingers. You can use any two colors for this trick, as long as they're different from each other.
Position your hand so that your palm faces you. Use all four fingers of your left hand to pull the blue rubber band toward you.
Reach underneath the blue rubber band to grab the green rubber band. Pull both rubber bands together with your left hand.
Close your right hand in a fist and stretch the portion of the rubber bands that you have pulled toward you around the closed fingers of your right hand.
Tell your audience that you will snap your fingers and make the rubber bands change places so that the blue rubber band will appear on the bottom around your ring and pinky fingers and the green rubber band will move to your index and middle fingers.
Snap the fingers of your left hand and open your right hand at the same time. If you have positioned the rubber bands correctly, their positions will now be reversed as if by magic.