One player stands on one side of the court, with three on the other who have a few balls each.
They throw balls to difference parts of the court for the player to run and dig.
In this drill receiver must be able to run constantly and dig balls on the move.
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.