Instructions
Clasp your hands together. Keep both thumbs upright and pressed against each other.
Create a void between your hands by widening the clasp of your fingers. Make sure you don't let air escape though.
Bend the tops of your thumbs over a little, away from you.
Open your mouth slightly and curl your lips around your teeth a little bit. Press you lips against the top joint in your thumbs then blow through and down into your hands.