Player underhand pass the ball from both sides of their body.
Before the next underhand pass is possible players must rotate their torso and then rotate again while passing.
Ask players not to stand lateraly to passing direction, their feet should be pointing forward and they only need to rotate their torso.
The higher your player underhand pass the ball the more difficult this drill becomes. This drill improves players' passing balance and ability when in an unnatural body position.
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.