Most of the French are usually members of certain societies, committees, public organizations. They like to name their status in full length. A similar list on your visit card will thrust them trustworthiness.
The French are often shake their hands. The shake should be energetic and strong.
If you are in a cab, shop or restaurant, it's natural that you say confidently "bonjure". Otherwise you'll be considered a villager.
Your clothes shouldn't be excessively expensive or namely French, but you should look fashioned.
Your hair and nails are very important. Your ring should be on his place.
Remember, during a business dialogue, do not scratch your nose. This is the equal of "A piece of cake". So it may confuse the French.