One mistake many coaches make is treat all ages the same when playing a sport. Sometimes that's a good thing while other times it's not such a great thing. This is because younger kids get their feelings hurt when you're yelling at them at what they're doing wrong so you have to say it a little nicer.
However, we don't run into that problem very often since after a coach has coached older girls, they usually don't want to coach the younger because it takes more time and explanation. This is because the kids are just learning and it's harder for them to take a lot in at once. Not only the way you act and the time commitment is different, the way you teach is way different too. You can't just explain to them something and expect them to do, you have to go through step by step showing them. Also, little kids may get frustrated and you as the coach might too, but just stay calm. Therefore, volleyball drills for elementary students or a lot of recreation teams have to be pretty easy and simple. It could just be something like 10 passes over the net or 10 serves or whatever you want as long as it's not too complicated.
When thinking up some volleyball drills for elementary students, you may want to think up some creative volleyball drills to go along with it. This is because they'll probably get bored easy since they're so young. If you're having trouble though coaching the young kids, you can always go to volleyball coaching clinics to help you out. As long as you have the patience and determination, you can teach anyone how to play volleyball!