While I have no law enforcement, or "lawyer-like" experience, I've been spending a fair amount of time with my local PD lately. A good friend is an assistant chief and I sometimes sit on the applicant Oral Board (the in-person interview board for people applying to be Officers). I'd sum up my comments in a couple of items:

- Always be polite. Most officers aren't jerks; but some are, and those are will look for ways to get you in trouble just because you are acting like a jerk.

- Unless you've been doing something wrong, or give them a reason to be suspicious (not answering questions is a GIANT red flag) officers almost always have good intentions. 99% of the time have better things to do than try to get someone in trouble who isn't already acting suspicious.

- If you choose to answer questions (and you should answer basic stuff IMHO), always tell the truth. If you get caught in a lie it makes everything about your interaction 100-times more difficult.

- If you choose not to answer any questions, for whatever reason, you should get to know your local/state laws regarding the things you MUST provide to officers when asked. Usually Identification is on that list, and choosing not to provide it means they can detain you.

- "Policing" has been changing dramatically the last 10 years. Most agencies are trying to use community outreach to improve relations, and in some cases fix their bad reputations. Some aren't, it's valuable to know that going into a situation, if possible.