Split players into equal teams, with each player having a ball. On the command the back player dribbles in and out of the players in front of them until they reach the front of the queue. Once they do the next person goes until they whole team have been.
Whilst the players are waiting in the line they should be bouncing their ball up and down.
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.