These are very short range sit ups with knees bent and feet flat on the floor keeping hands crossed on the chest.
Do not bring your hands behind your head.
Left towards your thighs and lower down until just where the lower back touches the floor and rise again.
Keep constant pressure on the abdominal muscles.
If this is too easy then lift your feet up off the floor.
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.