Overhead squat

Start in a squat stance with a barbell held overhead using a wide grip. Your arms should be fully locked out and stable.
Keeping your arms locked and actively pushing up on the bar, brace your core and begin to descend. Focus on keeping your torso as upright as possible.
Squat down until your hips are below your knees, ensuring the barbell remains stable and balanced overhead.
Drive through your heels to rise back to the starting position. Maintain the locked-out overhead position until you are standing fully upright to complete the rep.

Tips

Actively press the bar toward the ceiling throughout the entire squat, rather than simply holding it in place, to keep the barbell stable overhead.
Keep your torso as upright as possible during the descent by allowing your hips to sit back and down while your knees track over your toes.
Before you begin the descent, set the bar directly over your mid-foot so that it stays in that vertical path throughout the movement.

Allowing the barbell to drift forward in front of the head during the descent instead of staying directly overhead, which causes the torso to tip forward to compensate.
Bending the elbows during the squat instead of keeping the arms fully locked out, causing the bar to lose its stable overhead position.
Stopping the descent before the hips reach below the knees, leaving the squat range of motion incomplete.