make what you can, ahead of time
Greet guests with trays of their favorite cocktails or bite-sized eats. Set up a make-your-own cocktail bar to help keep guests occupied while you complete the final, finishing touches.
Designate serving trays for plates and flatware, appetizers, side dishes, and cocktails, to keep things organized and easily accessible for all. This way, you can move them around as needed, with little fuss.