Working in pairs, one player passes the ball and runs around their teammate before returning to their original position. The teammate then does the same.
By continuously running, players work on endurance while also focussing on passing.
If you want to add some speed to the drill, ask players to run as fast as and as many times as possible there and back before a teammate passes the ball over their head 10 times.
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.