Player contribution builds a four-legged stool of size, athleticism, skill, and game understanding (this includes psychology).
Game understanding requires time and teaching. Knowing where opportunity lies is a big part of experience. That allows the game to come to you.
Here are a few examples for young players to absorb:
When defense doubles the post, the rotation exposes the opposite wing as the 'open' area. Your reaction accelerates if you understand where to look. The game slows down.
Help side offense.
Helpside (weak side) offense must attend to spacing. Occupy your defender, set screens, and look for cuts to open areas on the opposite side of the split (yellow line bisecting baskets). You disrupt your teammates by crowding the ball side or cutting to occupied posts. Find ways to be involved without cluttering the middle.
Real estate is about location, location, location. Basketball is about movement (relocation). Players cut to the basket, to open spaces, to screen, or to move defenders. If 3 is a strong driver, the post relocates to open the driving lane.
Here 5 relocates to open the driving lane and become available when the help defender stops the ball, opening other areas for the post player. Sometimes helping means getting out of the way.