Your yoga practice starts with a solid foundation. In order to have a strong, solid, safe practice we must first focus on the feet. It is from the foundation that we grow our yoga poses.
There are four corners of the feet. There is the ball of the foot below the big toe, the ball of the foot below the pinky toe, the inner edge of the heel, and the outer edge of the heel. When standing, lift your toes up so you can press these four corners down into the earth and you can feel the arch lift up. Draw energy from the earth all the way up to your hip socket. Spread your toes long and gently place them on the floor without relaxing your arch. You'll notice that your muscles are now engaged all the way up your leg. By creating this strong foundation, you will find that you have more stability, ease and flexibility throughout your body.
From yogabycandace.com: "Focusing on the feet is a way to deepen your practice because
it requires the student to hone in on subtleties. A tiny movement or
shift in weight on the feet can impact the entire practice."