1. Always be calm, cool and polite. Never joke with cops- they don't think you're funny.
2. You have the right to remain silent, and you should.
3. You have the right to refuse searches, and you should.
4. Don't waive any rights.
5. Determine if you're free to go, then leave if you can.
6. Don't do anything illegal in front of the cops.
7. Don't run, and never threaten a cop- they will make you regret it.
8. Never touch a cop.
9. Be a good witness. Record or take pictures when you are able, and remember witnesses.
10. You don't have to let them in, so don't (unless they have a warrant).