When I first started coaching, I read a lot about Ethan Reeve, the head strength coach at Wake Forest University. He's not flashy, but he follows sound principles and makes his athletes work, something most need more of.
Coach Reeve loves the one-arm bench press. As a standard, he wants his athletes to press a 100-pound dumbbell for 5 reps. It offers a lot in the way of core anti-rotation strength. It also goes a long way in teaching full-body bench press tension.
Try to one-arm bench without braced lats, solid air, and your feet pressed into the floor.