1. Start with a wide triangle, and as your push-ups get stronger over time, bring your hands closer together.
2. Hands shoulder width apart, should hit right at your lowest rib. Elbows tucked in.
3. Shoulders forward: when David does his push-ups, his nose touches the ground about a foot ahead of his pants. Check out how he even comes up on the tips of his toes to get that forward motion.
4. Look slightly ahead of you on the mat to maintain spinal alignment.
5. If you can get the up, work the down! Practice lowering down as slow as you can without dropping your knees. Work on this until you can start to hold that low push up position, then "work the up," adding in the push.
Give it a shot!