It’s very friendly to start asking your pupils what would they like to learn or reinforce, what is the reason to learn the language for them, and then prepare your lessons fitting it. It may be useful to make a beginning prove to be aware of the language level they have and to arrange that, in the case you aren’t sure enough, and to choose making different groups or not. The Official Language Schools have a lot of exam models that can help you.

In addition, I think it’s interesting to ask for the way of structuring the lessons. By teamworks, via excursions, games (competitive? cooperative?), by topics, researches, etc.