In my experience, the French are delighted when travelers show a sincere appreciation for their country and there culture. One sure way of earning brownie points is by displaying an understanding of, and respect for, basic French etiquette. Here are a few tips for interacting with people while on vacation in France:

1. When addressing someone you don’t know, call them Monsieur, Madame, or Mademoiselle. Only add their last name to this appellation if you know them and only call them by their first name if you have been given express permission to do so.
2. Call a woman Mademoiselle unless she is clearly older or married. Some consider being called Madame the same thing as being told you think they look old, so be careful. Times are changing, but it’s best to error on the side of tradition until you know better.
3. Don’t begin a conversation in English if you are speaking to a French person. If you don’t know much French, then get started off on the right foot by being polite. Say “Bonjour, Monsieur” or “Excusez-moi, Monsieur” and then give it your best shot using your trusty French phrase book. You will have shown that you are polite and it will be immediately clear to that person that you don’t speak French. Not all French people speak English, but many do (especially in larger cities) and they will frequently come to your rescue by responding in English. Let it be their decision. You’ll get much better results.
4. When speaking French NEVER use “tu” with anyone that is not a relative, a very close friend, a child or an animal. To be on the safe side, you should ALWAYS use “vous”. Using “tu” with an adult that you don’t know personally is considered presumptuous, disrespectful, and insulting. It implies that you are either superior to them or that you are on intimate terms.
5. French people don’t smile at strangers, unless they are hitting on you or mentally unsound. It is not considered “polite” to smile and it is not considered “rude” not to smile. They prefer to carry themselves with reserved dignity and composure. They believe it is insincere to go around smiling at everyone and being overly friendly to people you don’t know.
6. When entering a store or shop of any kind, French etiquette requires you to extend a polite “Bonjour” to the shopkeeper and all contained within. It is considered very rude to ignore this basic courtesy and it will not go unnoticed. Equally important is to always say “Merci” or “Au revoir” when leaving.
7. When you are interrupting someone to ask a question or to request something, then ALWAYS say “excusez-moi, Monsieur”. This includes store clerks and waiters.
8. The French are a very private people and they tend to speak in hushed tones when in public places. Be aware of this and try to adjust your volume level, because by comparison Americans can seem very loud and showy.