The most important thing is that you get your players used to handling the basketball. You should make it so the basketball feels like it an extension of your hand.
Variations to try:
Around the leg, Around the waist, Around the head, Figure of 8.
There is an endless amount of drills you can do. Be creative and do them to start your workout.
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.