Spread your legs, bring your feet back, and place them firmly on the ground. Either your toes or your heels should be planted on the floor.
Arch your back.
Dismount the barbell using a grip that is a little over shoulder-width apart.
While holding the barbell, retract (push together) your shoulder blades and straighten your wrists.
Inhale as you lower the barbell to your chest, keeping your elbows tucked in at a 45-degree angle.
Exhale as you press the barbell back up to the starting position.
Comments and tips
Planting your feet, arching your back, tucking in your elbows, and straightening your wrists allow you to drive from your legs, through your body, and up through your arms—thus getting your entire body behind the press. Use this form to produce a strong foundation from which to press, increase your leverage, and give yourself a mechanical advantage.
Tucking in your elbows also reduces the pressure on your shoulders.
Never use a false grip. A false grip (aka thumbless or suicide grip) is when you don’t wrap your thumbs around the bar.