If your coach is always yelling at you to BOX-OUT you do not have good REBOUNDING HABITS.
On defense, EVERY TIME, ALL THE TIME an opponent takes a shot you need to have good REBOUNDING HABITS.
Your primary concern needs to be with getting into the EVERY TIME HABIT of attempting to box out.
Start by thinking about it and doing it one time, then two times, before long you will not have to think about it. It is now a HABIT that EVERY TIME an opponent shoots, I find an opponent and box him out. I don’t turn and wait for the ball to come to me.
Be aggressive, get your hands in the air, and go after that rebound. Attack the glass, rebounding is about positioning and boxing out but it’s also about ATTITUDE and ENERGY.