Stand with the feet about hip width apart and toes pointed out 15-45 degrees (tailor both to what works best for your anatomy). Dig the big toe into the ground, keep the feet flat on the ground and picture yourself ripping the floor apart using the feet, this will allow you to drive the knees wide and activate the glutes.

With the bar on the rack, get under the bar and place it on the upper back. Ensure that the bar is centered on the upper back. Tighten the back muscles by pulling the bar down and into your upper back muscles.

Take a deep breath in and tighten your core, allow the hips to slide back as you begin your descent (remember, the hips are what starts the movement). 

Sit the hips back and start bending the knees, descending until you land softly on the box. Do not allow the chest to drop and pay close attention to the even weight distribution in both feet.

While continuously driving the knees wide, push down on the ground with the feet to return to the starting position.