Start with a loaded barbell racked on a squat rack at chest height. If you're newer to the movement, use just the barbell, gradually adding weight as you become stronger.
Position your hands about shoulder-width apart on the barbell, and lightly grip the bar, palms facing away from you.
Step under the bar. Rest the bar on your clavicle and shoulders as you lift your elbows up. Your elbows should go as high as your mobility allows.
With your feet about hip-distance apart, lift the barbell off the rack. Take one to two careful steps backward.
Shift your weight back into your mid-foot and heels. Brace your core as you begin to lower into a squat, keeping your head and back straight. Your knees should be as close to 90 degrees as possible.
With your core still braced, drive through your feet to stand back up. Be sure to squeeze your glutes at the top of your squat. That's one rep.
When you're done with one set, carefully step forward and rerack the bar on the squat rack.