How to be Parisian
The clothes most tourists choose to wear in Paris make them really stand out as tourists. Somehow being on holiday gives some people the excuse to act entitled and underdress, looking disrespectful practically everywhere you go. You’ll stand out like a sore thumb; the Parisians can spot an ‘ugly’ tourist a kilometer away. Wouldn't it be better to be a little discreet and blend in a little?
People like observing people in Paris —that’s half the point of cafés and fashion; it’s as natural there as breathing. They’ll look at your shoes or your watch, check out what you’re wearing or reading. What they will not do is maintain steady eye contact or smile- so don’t smile at anyone you’re not willing to have some conversation with.
Say bonjour every place you go.
Any time you enter…anywhere — a restaurant, bakery, café, clothing store, pharmacy, art gallery, et cetera — immediately look for the closest person who might work there, and say "Bonjour" to them (or "Bonsoir" if it's the evening).
Whatever you do, never just start speaking English to someone. This is really rude and disrespectful. Even if you know everyone in your hotel speaks English, start with "Bonjour." You're a visitor in this country. Make this small gesture of respect. If you're brave, you can then ask in French, "Parlez-vous anglais?" If you're feeling a bit shy about trying some French, it's okay to lead with "Bonjour" and then, "Do you speak English, please?" If they do, they'll probably be more than happy to accommodate you.
Say Merci, au revoir every time you leave somewhere.
Whenever you're leaving any place — restaurants, museums, shops, et cetera — look back over your shoulder as you open the door, and say "Merci, au revoir!" to whomever is working there. Even if you can't see them, even if they're all the way in the back, even if they're in the middle of helping someone. There's an excellent chance that no matter how far away they are or how busy they are, they will quickly reply, "Merci, bonne journée/bonne soirée" (good day/good evening). If you walk out without the thank-you-goodbye, you're being a bit rude.
Keep it down.
French generally speak a lot more quietly in public than Americans do. Be mindful of this, especially in restaurants; if you stop and listen you'll notice the overall volume is much lower than what you're used to in the States. Try to match that level; don't be the table full of loud rude Americans!
No Such Thing as Overdressed
When you're going out and doing indoor things, like visiting a museums, or going out to a restaurant, think of how you'd dress for that same level of restaurant back home, and then dress nicer than that. There’s no need to go overboard; with a jacket and/or tie, but it'll make you feel really classy to wear them.
Parisians do not wear shorts, flip-flops, white sneakers, baseball caps, fanny packs, backpacks, oversized t-shirts, oversized jeans, oversized hoodies, etc.