Sit on the edge of an exercise bench, step, or stool and extend one leg out in front of you. Let your leg drop to the ground heel first, and mark the spot where your heel lands.
Stand with your feet shoulder-width apart. If you're using weights, hold a kettlebell in both hands in front of your chest.
Place one heel in line with the marked spot. Raise your other leg behind you, resting your toe/forefoot on the bench, step, or stool, aiming to balance your weight between your two feet. Your foot should be close to the front edge of the bench, but not so near the edge that you risk slipping off.
Bend your front knee to lower your body. As you sink down, your back knee will bend toward the floor. Focus on hinging at the hips and driving your glutes back toward the bench.
Aim to bring your front thigh parallel to the ground, but only lower yourself to a point where you're able to maintain proper form.
To return to standing, drive through the front leg, using the glutes and quads to bring yourself back up. Don't lock the front knee when you reach the top.