3 players in key, coach bounces ball in.
Everyone is competing for the ball.
Player who gets a shot in returns to the line and another player comes in. It is continuous play.
Focus on boxing out and rebounding - this can be done well if times from new player entering.
Good team defence is five players guarding the ball, not five separate one-on-ones. The shell drill is where that starts, so here is how to teach help-side positioning and rotations from the first week of the season.
Rebounding is the least glamorous thing in basketball and one of the most decisive. It is also almost entirely a habit, which means it is entirely coachable.
Good spacing is only the start. The best modern offences teach players to attack the defence's rotations and play in a permanent 4-on-3 - here is how to coach that read.