Thunderbolt Pose is a great for releasing tension in your feet. Sitting on your heels allows you to press into a natural pressure point in the arch itself. 

• Begin by kneeling on the floor with your feet tucked under you. Your knees should touch and your heels should be pressed flat against the floor. Lower your body onto your heels, and sit with straight posture with your hands resting on your thighs. Hold the pose for about a minute, and then lift yourself up with your hands pressed to the floor. Fold your legs back out in front of you and relax.