Mind your manners. The French manners are no joke, especially given the fact that there is no such thing as a small mistake, when it comes to it. You must know that in France big decisions will be based on the sum total of the small decisions. And these will be based on what you do appropriately & what you don’t. So, to be on the safe side, follow the example of the French & win that deal.
Don’t forget to use a French word every now and then. The French take their language very seriously, and so should you. When it comes to deal/no deal, this small thing may prove to be not so small after all. If you don’t believe me, ask a French.