Handshakes are business customs while greeting and leaving. The introduction of the handshake should be left to the top-ranking person except if you are dealing with a woman, in which case the action is left up to her. Firm handshakes are considered bad.
Using first names can be mistaken as annoying and rude. Use first name titles if you have been invited to do so. When you addressing people for the first time, try to use the last name, introduced by a French honorific such as Monsieur for Gentleman or Madame for Ladies. Using “Bonjour” while entering a place and using “Au Revoir” while leaving is considered polite and you can always reply with “De Rien” when somebody says thank you meaning you’re welcome.
La bise (the kiss), known for standard testimonial once there is an organized business association among women and men. Normally, it is a kiss, or more precisely an “air kiss” on two cheeks, first on the left side (for the other party), and later the right.
When working with French equals on different time prioritize etiquette and good responses. These points are dealt with high priority in particular business associations.