1) Don't have the mentallity of "Don't like what I don't like" People are very diverse.
2) Pay attention to what some people say about thier moods, it can be easy to start a chain-reaction.
3) If someone isn't taking "no" for an answer, don't start putting insults in your words.
4) if someone says "no" to what you asked, drop it; don't keep bringing it back up.