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.
Four players standing still make every ball handler's job harder. Teach V-cuts, L-cuts and back cuts so your team gets open and punishes defenders who overplay.
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.