Nate Beier: step up, jumping to a small box, jumping to a large box.

Sequence for box jumping:
Head forward. Torso upright. Feet just under the shoulders. Dip, drive, contact, extend. Step or jump down from box. Rinse and repeat.

What is wrong with this picture?
Notice the difference in extension. Can you reach full extension if you are looking at the ground?

Is the box jump scalable?

Stepping to a small box:

Jumping to a small box:

Jumping to a large box:

Common Faults:

Not dipping the hip before the drive, not landing on target, not reaching extension.

Build your own boxes: http://www.crossfit.com/discus/messages/26/14917.html