Best butt workout!!

  Sit on the ground with back against a bench, feet planted firmly in front of body, and a barbell fitted with a pad (trust, you'll want this) in lap. (No barbell? Try one heavy dumbbell instead.) 

  Keeping lower back and knees stable, push through heels and raise the barbell by extending hips, making sure to use the force of glutes rather than back.

  Rise until body forms a straight line from shoulders to knees (full hip extension), and then slowly descend back to the ground. Those work awesome for me. Try for two or three reps at least three times a week. And increase as you can.