With the bar racked around nipple-height, center yourself on the bar and plant your feet directly under it around shoulder width.With a short, sharp exhale, squeeze your glutes and tuck your ribs a bit.
Set your feet under the bar, at about shoulder-width apart. I’ve seen countless squatters in reader submitted videos who take the bar out in a split stance. This may work on lighter weights, but it will hold you back at maximum attempts because it can throw you off-balance.
A lot of people are going to stand back [away from the rack] and you know this is wrong because when they stand up, the bar comes [back instead of up] out of the rack... This will work at 50%-60% but once you get above 80%, it's gonna make the bar feel really heavy because you have to lever up with your back to get it out. Instead we need our feet to be forward and under the bar.
Before you approach the bar, exhale hard to allow the ribs to come down and the pelvis to come up and underneath you slightly... Get the air out to optimize your starting position, and then approach the bar.