Here is a basic yet challenging workout for the lower body and abs. The front squat -> back squat drop set allows you to use a moderately heavy weight for more reps than you would be able to front squat alone, which will increase the overload on the quad muscles. Start conservatively with the weight because your legs may feel a little shaky when first transitioning to the back squat. The session finishes with back extensions, lunges, assisted glute-ham raise, calf raises, and ab roll-outs done at a slightly higher rep range.
This would be an appropriate off-season workout for athletes that need to gain leg strength and size (football, rugby, bodybuilding, wrestling).