dividends. Don’t try and develop set plays. Don’t spend tons of time working on higher strategy like screening away from the ball. Work on dribbling, layups, defensive positioning, passing.
I have all the kids practice Mikans from day one, practice ball handling from day one, practice rebounding from day one, practice defensive position from day one.
If you want to work on more, teach them to cut to the basket after passing the ball and when catching a pass watch for the person cutting who just passed you the ball.
If you want one great exercise for practice, make them play one on one. The offensive player starts at the top of the key, the defensive player starts an arms length away. The offensive player gets only 3 (or sometimes 4) dribbles and then must score. If he scores he stays. If he fails he goes and the defensive player takes his place. Sometimes I only allow layups, no jump shots. This forces them to learn to beat their guy and have a move in mind and forces them to go hard to the basket instead of just dribbling around. Teach them to use the first dribble wisely to explode out and get their shoulders past the defender.
Watch a lot of YouTube videos on coaching kids.