We'll need a bit more information before we can try to help.
1. What age group(s) do you teach?
2. What level are they?
3. How many students are in each class?
4. What do you mean by "active"? Do you want them to move around more or do you want them to talk/engage/interact more?
5. What teaching method(s) do you currently use?
6. Do you teach at a school where teaching methods are somewhat imposed on you, or do you have an amount of autonomy?