These are all great suggestions. I'm happy that I've followed them consciously or unconsciously during my teaching career. I'd say the three most important rules are (1) the teacher should act like he or she is happy to be in the classroom with those kids -- every class is her favorite class and (2) the teacher should be consistent in enforcing rules -- don't let some kids get away with violations and others not, and (3) don't be lenient at the beginning at be more strict over time -- begin as a strict, consistent teacher and loosen up with time.