On the command the players dribble to the 1st cone before stopping and dribbling back to the start (whilst still facing forwards).
They then progress to dribble to the 2nd cone before dribbling back to the 1st cone and so on. Once they complete the relay they run to the back and roll the ball through the legs of their team mates to the person at the start of the queue.
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.
The ball screen produces almost half of all professional offensive possessions, yet most teams still teach it as a memorised play. The modern approach trains the read - giving players a framework to decide based on what the defence does, not what the coach called.