Players stand in pairs on the attack line, one player with a ball. That player throws the ball against the net, while the other player sprints forward, and dives to dig the ball up in the air.
The ball will never bounce off the net in the same way twice, just like players will rarely receive the same pass twice. Players need to be quick to react to where it will drop.
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.