Never get angry.
If a kiddo is giving you a hard time, take him/her to the hall and ask "Why are
you out here?"
If they say because someone made them angry, or made them do something, say,
"That's not it" and walk back in to the room leaving him/her out in the hall.
Come back 5 minutes later and ask the same question. If they don't own up to
the proper behavior, walk back in again. After your third trip out, usually the
response is "because I was talking when I wasn't supposed to," or something
like that. Ask if they "know the rule" and if can refrain from continuing said
behaviors(or they will be sent to the office, stay after, whatever), smile and
let them back in. Do not lose your cool.
I have only one rule, "Do nothing to hinder teaching or learning." It fits