When I do a back squat my heels are about 14" apart with my feet parallel.
I go down by moving my knees forward first, until my ankle flexion is maxed, then proceed to an Olympic depth.
My elbows are forward and under the bar to promote thoracic extension. Stomach is in. Eyes are forward, not up.
When I'm coming back up my hips don't raise before my shoulders. At the halfway point, my hips press forward to finish the lift.
It's an extremely clean 305# x 1 with no belts, wraps, or suits.