*   Electric outlets in France may not the ones you have at home.
*   Local time is given in "24h a day" frame: "6.00 pm" is "18h".
*   There's no tipping obligation except for Taxi (half a Euro for a local ride).
*   In a restaurant, if you really enjoyed the meal/service, you can leave a small tip, but 10% or 15% above the bill is not expected, as customarily service is included in the price of the meal.
*   A weekly public transportation card is convenient and cost-effective. It goes from Monday to Sunday. Bring a photo.

In case you were wondering :
*   French people are generally nice; even Parisians are nicer than often thought; but…
*   Restaurant service may be impatient: this is NOT personal nor particularly against tourists, we experience it ourselves everyday and that is one of the reasons we like so much... to travel abroad
*   Avoid asking "Do you speak English" - As some French people believe that perfection is possible. Also some Parisians may be reluctant to admit that they do, even when they can manage quite well. Our suggestion is -- simply try in French (broken or not)... the Parisian always appreciate the effort and the rest will take care of itself.