Build those glutes with donkey kicks.
Directions:
Get on all fours, with your hands aligned with your shoulders and your knees aligned with your hips.
Keeping your back straight, push your right foot out to the imaginary wall behind you while keeping your leg straight.
Your foot should remain flexed (toes pointing down to the floor) throughout. Take care to keep your hips square to the ground. Squeeze your buttocks at the top.
Return to the starting position. Repeat for the desired number of reps. Repeat on the other leg.