Press your middle finger and thumb together with your pinky in the hollow of the gerl of your hand and your ring finger slightly overlapping it at the base of the thumb. Move the thumb out of the way to the side, allowing the middle finger to accelerated down to strike the spot where the ring finger meets the base of the thumb.

How I learned? In a dream. I literally woke up snapping my fingers and I’ve been able to do it ever since.