I recommend dressing like the locals - probably something very simple but elegant - not too
casual (no t-shirts with big logos, etc.).
wear shorts! When I was there last, 3/4 length pants were all the rage for both men and women - especially in white. I got a pair of these in Germany, as that fashion was popular there too.
If you think you won't be able to tolerate the heat without shorts, get one of those cooling bandanas. You soak it in water; crystals inside absorb the water so when you tie it around your neck, it cools you down. It works! Europe seems to be getting hotter and hotter.
A simple tote bag is preferable to a bulky backpack - just hang on to it when in public. I advise against carrying a camera in plain view.
A few other pointers - don't raise your voice. I notice Americans tend to talk to each other very boisterously when abroad (I serve as a tour guide to many of them
). This is a dead giveaway that you are a tourist, and something that locals might find unattractive. Chewing gum is another thing to skip.
Do try to learn a few basic phrases of French, and ALWAYS
to a shopkeeper when entering their establishment. It is also polite to say merci
when leaving the shop. Don't be afraid to shake someone's hand when you meet them.
I could go on
but this is a good start.
Even if you do all these things, the French will probably still see you as a tourist - but they will almost certainly appreciate your efforts.
Just keep in mind that there are thousands of tourists in Paris at any given moment - you will be one of many.
Oh one more important thing for travelling abroad: pack light! You can probably halve the amount of stuff you think you need, and then halve it again. You'll be glad you did.