1. Start with the feet about shoulder width apart and slightly toed out.
2. Keep your head up looking slightly above parallel.
3. Don’t look down at all; ground is in peripheral vision only.
4. Accentuate the normal arch of the lumbar curve and then pull the excess arch out with the abs.
5. Keep the midsection very tight.
6. Send your butt back and down.
7. Your knees track over the line of the foot.
8. Don’t let the knees roll inside the foot.
9. Keep as much pressure on the heels as possible.
10. Stay off of the balls of the feet.
11. Delay the knees forward travel as much as possible.
12. Lift your arms out and up as you descend.
13. Keep your torso elongated.
14. Send hands as far away from your butt as possible.
15. In profile, the ear does not move forward during the squat, it travels
16. Don’t let the squat just sink, but pull yourself down with your hip flexors.
17. Don’t let the lumbar curve surrender as you settle in to the bottom.
18. Stop when the fold of the hip is below the knee – break parallel with the thigh.
19. Squeeze glutes and hamstrings and rise without any leaning forward or shifting of balance.
20. Return on the exact same path as you descended.
21. Use every bit of musculature you can; there is no part of the body uninvolved.
22. On rising, without moving the feet, exert pressure to the outside of your feet as though you were trying to separate the ground beneath you.
23. At the top of the stroke stand as tall as you possibly can.
-from CrossFit HQ