I am always pleasantly surprised how sore my butt is when I add this simple move, which combines a sumo squat with a standing side crunch, to any workout. This bodyweight exercise is not a plyometric move, but springing up from a deep sumo squat to stand on one leg is really effective for activating the glute muscles. And adding the side crunch works the abs nicely too. And these are two areas of my body I always like to work.
Since this move requires no weight, you can really do it anywhere or anytime.