Divide the court into 3 equal areas with a line across the length of the court. (6m x 9m) 8 players per small court.
For every team, the following rule applies, after the ball is thrown the team rotates clockwise one turn.
Throw the ball across the net first time using either:
An under arm throw with straight arms, a one arm overhead throw or a one straight arm underarm throw.
These are all typical volleyball throws related to the real actions.
New hitters rarely miss because of their arm. They miss because of their feet. Build a reliable approach, then time it with your setter.
When your hitter gets stuffed, five teammates standing and watching is how you lose the point. Good attack coverage turns a blocked ball into a second swing.
Coaches spend hours correcting arms in serve receive when the real fault is almost always the feet. Fix the movement and the platform fixes itself.