Two groups of players with one ball and one player between the groups on the side.
Player 1 passes to player 3 and runs straight to receive a pass from player 3. Player 2 then makes a pass to player 3 and makes and runs to receive a pass before passing to player 4.
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.