Fold two simple paper planes together and put a box on the floor about three metres away.
Take turns throwing. After each throw, ask one question: 'what will you change next time?'
Move the target closer if nothing lands, further if everything does. The aim is a hit rate around half — frequent enough to stay interesting, rare enough to require adjusting.
Overarm throwing coordinates the whole body — stance, rotation, release timing — and a visible target makes each attempt a measurement. Asking what will change next converts random repetition into deliberate practice.