Always be calm and cool.  Police are allowed to have bad attitudes but you can't be rude, talk back, or use profanity.

You have the right to remain silent.  Tell them you wish to remain silent and tell them you want a lawyer.  Don't let them intimidate you into talking as they will twist your words and use them against you in a court of law.

You have the right to refuse searches of your person, car, and home.  Tell them you don't consent to searches.  Don't allow them to scare or trick you into searches without a search warrant. 

Don’t get tricked into waiving your rights.  Police are allowed to lie to you yet you can't lie to them.

Determine if you’re free to go. Ask if your being detained and if your free to go.

Don’t do anything illegal.  Even if you feel that the law is unconstitutional.   Police don't care about the Constitution.  Only about arresting criminals.

Don’t run.  It's an excuse to criminalize you and once they catch you they may treat you in an extra aggressive manner.

Never touch a cop.  They can charge you with felony assault just for touching them.  You could also get tasered or beaten.

Report misconduct. Be a good witness.  However don't ask for a badge number or indicate your going to report them.  They may take it personally turning the situation into something potentially dangerous.

You don’t have to let them in your home or car without a search warrant.   Don't let them trick you into letting them in as they are allowed to lie to you.