My clients know that Supermans are one of my favorite exercises. One of my clients dislikes them so much that she said supermans actually make her "feel angry". Regardless of the anger that may or may not be a by-product, supermans are another one of nature's perfect exercises: you can do them anywhere, you do not need any equipment, AND you work almost every single muscle in the back of your body. (And a strong back is essential to maintaining your posture, and to being, well...strong.)
Try the X-Superman to add some variety.
Start face down, flat on your stomach on a mat. Open both your arms and legs about as wide as your mat. Rotate your arms and turn your thumbs to the ceiling. Slide your shoulder blades down, squeeze them together slightly and lift your arms and legs at the same time, keeping the "X" shape. Stay lifted for a count of 3, lower, then slowly repeat. Make sure to exhale on the way up, inhale on the way down. Do 20 butt and back kicking reps.
BRILLIANT. EASY. BESPOKE.