Sometimes it is nice to mix it up and what I mean is, several players have the knack or ability to serve unique serves. As a coach I think you should exploit these talents. Many coaches work on a particular style or type of serving and encourage their whole team to use that method. I think it is best to experiment in practice and find out who can do what. Obviously everyone wants their kid to serve the floater that flies like a dart, but there are many other serves that can be productive. For years everyone felt that a topspin serve would basically pass itself if you got your platform there. That’s not always the case. The setter from Penn State had the awesome topspin going to the far corner. That serve made me nervous and I was in the nosebleed section of the arena!
Some kids serve the same style that they did in junior high because they were successful with it. If you get them to try something new they may find that they have a real gift for a different serve. Some kids are not comfortable changing their style, but it is good to see what they can do. Some of the things that I have had kids experiment with are things like a deep, deep hard floater from as far back as the basketball baseline on the court. Some of the kids that master this serve have so much pace on the ball that by the time it crosses the net it has created a great deal of friction in the air and really skids side to side dramatically. I like topspin serves, your kids that also play on the tennis team will be really good at these. If you can find someone who is comfortable hitting a slice it can cause a lot of confusion for the receiving team. Of course jump servers can cause issues as well. Finding someone who is consistent serving short and deep is valuable too.
Once you find who is strong at different serves I recommend not having three or four servers of the same style in a row. One year I had two players, one served right slice, and the other served left slice, so I put them close to each other in the lineup so the receivers had two extremes to deal with. If you get six players on the court that all have a unique serve it would be advantageous. I haven’t had that yet, but came close a few times.
Of course the goal of consistency has to be met and the serves must be tough. So for a kid to focus in practice on upping their serving game is what needs to happen. Too often coaches say, “Okay serve for ten minutes” or “Serve fifty in serves” but are they really getting the max out of that practice time?
Try it if you like, experiment, and hope you and your team have fun with it.