Knowing how to wedge the bar out of the rack and properly unrack a bar to setup for a squat is not emphasized enough by coaches. Starting in a good positions allows the lifter to continue to be in the best position possible. If a lifter sets up properly and gets the proper pressures and postures, they set themselves up for success. Too often lifters will shortcut and rush unracking the bar on a squat and thus makes it more difficult for them to find the proper positioning and tightness. Some of the most common faults are that they don't lock in the lats or unrack with uneven feet.
Levi here is squatting out of a monolift and in powerlifting briefs, but the same principles follow for anyone lifting. Foot tension into the floor, big air and brace into the belt, hips under the bar, back tight, squeeze the bar out of the rack by extending through the legs.