Exercise No. 1
Lean forward against a wall, keeping one knee straight while you bend the other knee. (If both of your heels hurt, then you need to reverse this position after you have exercised each heel. If only one of your heels hurts, the painful heel is placed farther away from the wall.) As you bend forward, the leg that remains straight is the one that you will be exercising. As you lean forward, you can feel your heel and the arch of your foot stretch. (Try to keep your heel on the ground, although as you stretch it, it will gradually lift off the ground.) Stretch and hold for 10 seconds, then relax and straighten up, then stretch again. Repeat this 20 times. If your other heel bothers you, then you should stretch this side as well by reversing your position.
Exercise No. 2
Lean forward as you lean onto a table, chair or countertop. In this exercise, you will flex both of your knees. Squat down slowly. Try to keep your heels on the ground as long as you can as you squat down. You will feel your heelcords and the arches of your feet stretch as your heel finally starts to rise off of the ground. When you feel these structures really stretching, hold that position for 10 seconds, then straighten up. Repeat this 20 times.