Hold two rubber bands in your hands. As you talk to the audience, stretch the bands, play with them and make them prominently visible so it's clear to your spectators that there are definitely two separate bands.
Speak to the audience to hold their attention. When they watch your face, casually drop one of the rubber bands out of sight. Continue speaking directly to the audience; you must give the impression that you're absentmindedly playing with two bands.
Place the elastic band on the thumb and index finger of your left hand. Holding your index and middle fingers together on your right hand, place them in the center of the band. Twist the band into a figure eight.
Keep the band taut as you reach beneath, up and around with your thumb. Holding the band in the webbing of your thumb, slide the tip of your thumb into the top of the figure eight. Remove your index finger, leaving your thumb and middle finger inside the loop.
Pull the band taut between your thumb and index finger of your left hand, and thumb and middle finger on your right. Done correctly, it appears to be two separate bands.
Roll the rubber band slowly off your right hand and into a ball between your index finger and thumb. Say some magic words or have an audience member blow on your hands for luck. With showmanship, throw open your empty right hand. Only one rubber band remains on your left hand.