Stand just in front of a bench, box, stair, or chair, facing away from it, and hold a dumbbell in each hand by your sides. Extend your left leg backward to place the toes of your left foot on the bench.
Make sure your right foot is out far enough so that when you lower your hips, your knee stays directly over your ankle. (This may take a little adjusting.)
Bend your right knee, squeeze your left glute, and lower your pelvis toward the ground. Pause when your front thigh is parallel to the ground, or you've gone as low as is comfortable.
Press your right heel into the ground to straighten your right knee. That's one rep.