Lie flat on your back with your feet flat on the ground, or resting on a bench with your knees bent at a 90 degree angle. If you are resting your feet on a bench, place them three to four inches apart and point your toes inward so they touch. Place your hands lightly on either side of your head keeping your elbows in. Don't lock your fingers behind your head! Push the small of your back down in the floor to isolate your ab muscles. Begin to roll your shoulders off the floor. Continue to push down as hard as you can with your lower back. Your shoulders should come up off the floor only about four inches, and your lower back should remain on the floor. Focus on slow, controlled movement - don't cheat yourself by using momentum!