Three players make a triangle while another joins one of the corners with a ball.
The player passes the ball to another corner of the triangle before following the pass and standing behind the receiver, who continues the drill.
In this drill players develop endurance while passing for 5-10 minutes with no stoppage.
To involve more speed there might be more players in corners and their task would be to pass and run around the whole triangle and return to start posiiton and get ready for next pass.
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.