In pairs, the players face each other.
Player 1 throws the ball underarm to his/her partner.
Player 2 receives the ball using a dig method, and hits it high in the air, lets it bounce once, and then returns the ball to his/her partner using the underarm pass method.
This drill develops both the passing, positioning and receiving skills of your player.
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.