Small circle

Practice your peng extensively against different types of attack.
Determine the necessary frame size-to-waist turn ratio in order to employ peng appropriately for your height/size and inclination.
Explore the effect of different considerations:

1. 3-D
2. 70/30 stance
3. Waist to weighted foot relationship
4. Range
5. Angle of attack
6. Type of attack

Ideally, you want to find and take the balance immediately upon contact. A very small waist turn will lead the attacker upwards, severing the root.