General suggestion: get some background information on coaching, and particularly coaching kids in the age range(s) you're teaching. It's very helpful. In fact, I'd say in general that this is the sort of approach you want to take in teaching anything to anyone: develop an understanding of the student and move toward your subject from there (if that makes any sense), rather than starting from your subject and trying to figure out how to teach it to your students. Information can always be given, but I think teaching has to go in the other direction -- otherwise it's like pushing a rope.
Couldn't agree more. You might find your local college may run coaching courses or your national sports federation (I don't know the structure in Denmark but that's how it works in the UK).
Glad the drill idea helped.