Relax and stand on flat feet, feet shoulder-width apart.
Squat down and stretch out your left foot, with your toes pointing upwards, with your weight on your back foot. Head, spine, and the back foot forming a vertical line with the ground. This is a defensive posture.
Move the center of gravity forward, keep both feet firm, and divide the center of gravity equally between the two feet. This is the center stable posture.
Move the center of gravity forward, with the center of gravity on the front foot. Head, knee, and the front foot forming a vertical line with the ground. This is the offensive posture.