Each player has a ball no matter what position they normally play on the court. Each player starts with the ball on the floor.
The first step is for the player to put his/her fingers on the ball like during overhand passing - that is fingers extended and wrists flexed towards forearms.
The second step is to pick the ball up and start bouncing it with no change to the way their hands are positioned.
Have players bent over, rather than in a squat position, on this drill.
In this drill players will master the way their hands should be and get used to how to touch the ball for a overhand 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.