Set out the cones as shown in the diagram. One player starts with a ball with two other players starting in the middle of the cross (compass). One player is an attacker with the other a shadowing defender.
The player with the ball has to pass the ball to the attacker, who then passes the ball back. The attacker must then run to another point (cone) of the compass before returning to the middle to receive another pass.
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.