Groups of 3 each have a ball. If you had a large group of 12+ use both ends of the court. Trio elect two attackers (A & B) and defender (C).
(A) passes to teammate (B) who runs into the goal circle and receives at least 3m from the post
(B) should have a moderately difficult shot, the focus of this drill is defending and rebounding
After passing, (A) tries to run into the goal circle and get the rebound. However (C) makes this as difficult as possible, as they want to retain prime rebounding position.
(C) blocks (A) by putting their body between (A) and the post, keeping them on the outer
(B) shoots. A successful shot ends the contest, if not, (A & C) contest the rebound. Regardless of who wins the rebound, trio run off court and next group assume starting positions and start their turn.
For junior teams, rotate roles for next turn; advanced teams you may want players to remain in preferred positions each turn.