What to beware of with the French?

10 French “Faux Pas” & Cultural Mistakes From an Insider's Perspective : The French Etiquette

1 - Don't get too friendly too soon. ...
2 - Don't be too direct and use polite expressions all the time. ...
3 - Don't smile too much. ...
4 - Don't be too enthusiastic. ...
5 - Avoid certain topics: religion and money.

Is it insulting to tip in France?

Tipping is not required in France (although there are a few exceptions). You don't need to tip French waitstaff because they get a living wage and benefits. It is NOT considered rude to tip in France. There is no standard percentage for tips in France.