Answer:
Just a short handshake and no kisses is typically seen as rude(depending on who you're talking to).
Accepting objects with your left hand(in Algeria).
Making the "okay" sign.
Snapping(in Belgium).
No greeting and/or farewell to everyone.
Eye contact(typically with strangers)in public spaces.
Talking loudly in public spaces.
Not opening a gift right away and not showing appreciation.
Leaving food on your plate.
Things that ARE acceptable
Handshakes when greeting people who do not know each other well.
Kissing each other lightly on the cheek is used between people who know each other better.
French people use first names when speaking to each other ONLY for family and close friends.
Bonjour/bonsoir followed by Monsieur/Madame is used to greet shopkeepers and some others.
When in public spaces, no eye contact and keeping a low voice.
When giving flowers, there should be an odd number of flowers and if a funeral bring white lilies or Chrysanthemums, no red carnations, white flowers at weddings.
Arrive on time be no later than 10 mins, if you must, send flowers, you should dress well.
There's more, but these are just a few popular ones.
