Use a mirror or window to look at your form and technique.
Whether it is passing, shooting or dribbling.
The feedback you get from seeing yourself is unbelievable. A lot of mistakes players make, they don't realise they are doing because it is a habit. The only way to change is to see what you are doing wrong.
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.
The ball screen produces almost half of all professional offensive possessions, yet most teams still teach it as a memorised play. The modern approach trains the read - giving players a framework to decide based on what the defence does, not what the coach called.