the fundamental principles of teaching

INNOVATION IS ONLY BOUND BY A FAILURE TO SEE THE FUNDAMENTAL PRINCIPLES OF PLAY. - Katie Salen, Rules of Play: Game Design Fundamentals

I would modify the last word to "teaching".  Once you understand that the fundamental principles involve:
1. showing the purpose of what the students are about to learn
2. helping the students realise what knowledge they're missing
3. providing a way for them to acquire the missing knowledge (direct teaching isn't the only way!)
4. providing a way for students to communicate their new knowledge in a meaningful way
then you can be boundlessly creative