Wash your hands. Prior to putting your digits in your mouth for a practice session, it's a good idea to ensure they're clean.
Tuck your upper and lower lips over your teeth and into your mouth.
Choose your finger combination. Most commonly, the thumb and middle, or index finger are used in a U-shape, but it is possible to use the index fingers, middle fingers, or little fingers from each hand if preferred. Practice to see what is most comfortable.
Position your thumb and finger or two fingers in your mouth with your fingernails angled inward toward the center of your tongue. Press your fingers down to pull the lower lip taut.
Draw the tongue back to broaden it. Hold it behind the lower teeth, about 1cm (1/2inch) behind the lower lip.
Exhale over the tongue and lower lip and out of your mouth. The air forcing itself between your tongue and upper lip should create the whistle.
Adjust your fingers, the angle of your tongue and the force of your breath until you find the most effective position.
