Take a test
Take the time to answer a few questions on decorum to revise your good manners.
You should arrive 15 minutes late. In France, it is appropriate to arrive 15 minutes late, the famous “Parisian quarter of an hour” which allows the hostess to deal with any last minute unforeseen circumstance. In the event of a reception, 30 minutes behind schedule is quite alright.
You serve their bottle immediately. It is appropriate to taste the champagne you are given immediately and to thank your guest (discretely) in order not to embarrass other guests who may have arrived empty-handed.
Half folded on your knees. Your napkin is to be used to wipe your mouth before and after drinking. If you are using your cutlery appropriately, you should not need your napkin to wipe your hands… And only once you have finished your meal should you place your napkin to the right of your plate.