6 Players with 2 balls. The Coach decides whether to start the practice going clockwise or anti-clockwise. If you are one of the two middle people (players 1 & 2) then you change with each other once you have passed a ball. If you are on one of the corners then once you have passed your ball you exchange places with the person on your diagonal, e.g. Player 4 exchanges with player 5.
Four players standing still make every ball handler's job harder. Teach V-cuts, L-cuts and back cuts so your team gets open and punishes defenders who overplay.
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.