Close your lips lightly and keep your mouth relaxed
Place your tongue behind your upper teeth
Curl your index fingers slightly and press the finger pads against the corners of your mouth
Seal your lips around the fingers as much as possible without biting
Create a small gap between your fingers and the center of your mouth
Blow a focused stream of air through the gap while keeping your cheeks firm
Adjust finger angle and spacing until the pitch stabilizes
Try different finger positions: closer together for higher pitch, farther apart for lower pitch
Keep the airflow steady and short bursts to refine control