One of the most unfortunate realities of hosting a holiday gathering is that you often end up spending the entire night in the kitchen completing last-minute preparations and trying to keep up with the dishes. If this is the case, make sure you are able to enjoy your guests by bringing the party to you.
More Cooks in the Kitchen: Rather than shoo would-be chefs out of the kitchen while you season, stir, and cook, invite everyone in! Purchase inexpensive aprons at craft stores for adults and older children who will be attending your party. You can even put their names on the front or otherwise decorate the aprons if you'd like.
Identify tasks such as peeling potatoes and slicing carrots, and write those tasks on slips of paper. Put the slips into a hat, and let each guest draw a task with which they can assist or which they must complete in full. It generally will take each person only a few minutes to complete their task (unless some poor soul draws "Make Creme Brulee from scratch—blow torch in pantry"). This approach saves the host several hours' worth of work, plus it's a fun activity to do as a group.
The Art of Pot Luck: Another idea is to let those on the guest list know what the main entree will be a few months in advance. Ask them to come up with a side dish, appetizer, or dessert (or a combination thereof). If the guests are local, ask them to prepare and bring their selected item. If they are out-of-town guests, ask them to provide you with the necessary ingredients so that you can purchase them ahead of time. Your guests are then responsible for preparing their recipe. Everyone shares in the meal preparation, and there's an unexpected and welcome variety to the menu, too.
Embrace Frozen Food: If you insist on preparing the entire meal yourself, don't discount the convenience and quality of frozen appetizers or side dishes from establishments such as discount grocers or warehouse clubs. One year a friend of mine used frozen items from a warehouse club for her entire Christmas menu—appetizers to dessert (she made me promise not to use her name in case her in-laws read this). No one was any the wiser and it was the easiest holiday meal she's ever prepared.