Timing for Flicking Your Front Foot
Mechanism / Why It Happens
Pull your front foot in before you flick
As mentioned earlier (Link), you should apply a downward diagonal force to the board. When you pop the tail, the nose rises—at that moment, press your front foot against the nose and pull it in toward your body. By pulling it in sufficiently before you flick, your foot will swing diagonally downward around your knee. In other words, if you pull your foot in enough, your body naturally generates a downward diagonal force due to its structure.

What to Do
Practice only the motion of pulling your front foot in
The harder you try to flick your front foot, the more unnecessary tension builds up, making it