To hit a solid pistol squat, you need mobility, strength, and balance. Use this exercise regression to work your way up to a full pistol. As with all pistol variations, keep these cues in mind:
Focus on a spot on the floor and extend one leg in front of you.
Sit back in your heel as you push your hips back and drive your knee out.
Focus on pushing through the heel, big toe, and pinky toe as you extend your knee and hips.