Wash and dry your hands
Make a loose fist with both hands
Leave a small opening between your thumbs
Place your thumbs together and your knuckles against your cheeks
Tuck your lips slightly over your teeth
Put the tips of your thumbs under your tongue
Blow forcefully through the opening between your thumbs
Adjust the angle of your hands until air flows cleanly
Tighten or loosen your lips to change the pitch
Practice with small changes in hand position and airflow
Keep your tongue relaxed and slightly back
Repeat until you find the position that produces a whistle