1: Always remain calm and communicate in a respectful manner. When you disagree, start your sentences this way "Officer, I know you are just doing your job but ..." Never use profanities and never raise your voice even if the police shouts at you.
2: You have the right to remain silent. The 5th amendment makes it illegal to force you to be a witness against yourself.
3: Say "I don't consent to searches" if the police asks or attempts to search your person or your property. If you consent then you may not be compensated for items damaged during the search. Also, you may be charged with crimes that you didn't even commit, like your buddy who borrowed your car last weekend leaving a marijuana bud in your car.
4: Even if you refuse to consent to searches, the police can still search you albeit unlawfully. Remain calm and do not resist. (If you resist, you will be breaking the law and endangering yourself.) Remind yourself that the evidence they may find during an unlawful search can be challenged in court.
5: Also know that if your car or home door is left open by you, the police can search your property without warrant. So, keep your property secured at all times.
6: Police may lawfully order you out of your car during a traffic stop. You have an obligation to comply. Do so promptly, but without any sudden movements. Say "Sure" in a calm but audible voice, exit your car and close the door behind you.
7: Police can legally lie to you. Don't believe their statements and threats without verification from your lawyer. They may be bluffing to make you confess to anything you may or may not have done.
8: If you were not told that you are under arrest, ask the officer "Are you detaining me or am I free to go?" If they say that you are not detained, you can just leave.
9: Don't expose yourself to the police. If the police sees something suspicious like empty baggies in your car that you may be using to carry your lunch, or a toy gun that looks a bit too realistic, they can lawfully search you without warrant and put you under arrest.
10: Don't ever run from the police. Follow their instructions even when they are acting unlawfully.
11: Never touch a police officer. State your refusal only verbally. Never resist physically. Every time you express your refusal, say "I am not going to resist, but I am not consenting to your actions."
12: If you are put under arrest, say "I am going to remain silent and I would like to see a lawyer." Don't answer any questions until your lawyer arrives. They will keep asking, so don't cave in.
13: Don't sign anything until you have read it yourself and your lawyer has explained it to you.
14: Don't ever invite or let police into your apartment or house without a signed search warrant. If they wanted to talk to you, do the talking outside your door and keep the door closed behind you.
15: As of 2012, videorecording on-duty police in a public place is legal as long as it is done openly and without interfering with their operations. If you can, stay at least 15 feet away and if they ask you to turn off the camera tell them "Officer, I am not interfering. I am just a citizen openly documenting the actions of a public officer. It is my first amendment right."
16: If you possess a videorecording of an unlawful police action against you or others, do not share it with the police unless the court orders you to do so. Instead, upload it on Youtube under an anonymous account. Otherwise you can be charged with eavesdropping by the police in 12 states including Illinois. Although all such charges in the past have failed, still you don't wanna go through the stress of an added legal confrontation.
17: The police may not require you to provide an official ID. However, in 24 states you are required to identify yourself to the police if they have reasonable suspicion about you. Just say "I am not required to show you an ID, but my name is [Your full name]."