Players start in two lines: either at the half way line or behind the 3 point line.
For a right hand lay up:
The 1st two players in the right hand line start with basketballs. The first player dribbles to the basket and makes a lay up and leaves their shot and joins the back of the left hand queue.
The 1st person in the left hand queue moves to collect the rebound and passes to the next person without a ball in the right hand queue and joins the back of the right hand queue.
This then repeats. This can be done on both the right and left hand sides.
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.