Lie on your side with a neutral spine. Do not side bend. Maintain a slight lift of your waistline away from the floor. Do not sag toward the floor in your waist.
Let your head relax into your arm or a pillow.
Keep your upper back, middle back, buttocks and feet in a similar line. Do not back bend.
Bring your top hip slightly forward of your bottom hip so that your knees are aligned. Your top knee might also be slightly forward of your bottom knee.
Stack your pelvis and do not let your pelvis move during the movement.
Move your top leg without moving your pelvis or your spine. The only thing that moves is your thigh bone.
Move your thighbone only as far as you can without allowing your pelvis to move. Your pelvis should stay perfectly still.
You should feel this in your lateral, upper butt (just above your jean pocket). If your calf, thigh or other body parts start to cramp or get tired, relax. Over time you will be able to isolate the movement to just your upper butt.