Go in with a plan of action. Know exactly what you will be preparing and what needs to happen in order for it all to be prepared. Also importantly, is to have lots of helping hands to assist you.
I suggest you make the porportions small so that not as much ingredients are needed and that the dish is easy and fast to make to not keep people waiting.
Feeding the multitudes? Appetizers are a great solution. Recipes that can be prepared "assembly line" style include chicken wings, stuffed mushrooms, potstickers and meatballs to name just a few.