In pairs, one player rolls the ball out along the floor.
Ensure the players run past the ball and the ball approaches them. This mimics the game as player should always be behind the ball and facing the target where they want the ball to go.
Timing is also crucial and teachers players special awareness and control of muscle movements.
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.