Here is a video of a good drill but there are many used by today's coaches and I'm sure the Bruins have their own rebounding drills but I don't know what they are. All teams have rebounding drills though including blocking out techniques. Solid rebounding is one of he basic basketball skills that is critical to a team's success and all coaches know that.
Excellent rebounding depends on quite a few things though. Some physical and some mental. Some can be taught and some are instinctive.
For individual players, some of these things include a combination of physical and mental traits including things like reasonable height, strength and very important--strong hands, good athleticism, agility/quickness, good mental focus and timely court awareness relative to boxing out and anticipating the ball's probable direction off of the rim. Unfortunately, not all players have all of these capabilities.
One more extremely important thing. A player has to have a burning desire to be a good rebounder to actually be one.