Bill Phillip's Back To Fit: Day 38
The lower body is the start of everything good and noble in the muscle universe.
No one with any salt will dare skip leg day. Learn this. Know this. Your legs will grow to carry you. Don't overlook the importance; we can't impress upon it enough.
On the glute bridge: put a towel on your lap to avoid any direct pressure from the barbell. Don't let your back slide up or down the bench or floor. Just use your hips to complete the movement. This will work your glutes of course, but also your posterior chain.