Start at one basket. Line up your offensive players in any spots you want. The defense will play man to man. The object of this drill is for the defense to get out as quickly as possible. The score begins 3-0 in favor of the offense. Every time the defense gets a rebound, steal, block shot/recover, the score goes down to 2-0. Every time the offense gets a score or offensive rebound, it goes back up to 3-0.
Have one team in blue and one team in white. The rest of the players should stand under the hoop. You can break it down into 3 groups of 4.
Emphasize blocking out with a low base and hands high. Also, emphasize contesting the shot with the left hand if it is a right-handed shooter, and vice-versa.
You can also use this drill if you want to work on half-court offense or half-court defense. You don't have to do it just for rebounding purposes.
Blocking out, communicating
This basketball drill is licensed under a Creative Commons License. This drill is from Pål Degerstrøm at www.degerstrom.com/basketball.