You can minimize the damage with a little forward planning and mental preparation.
Don't save up by not eating. Your body compensates by lowering your metabolism to guard against starvation. When you do eat your body will just soak up more calories and store them as fat for later.
Go properly fueled. Eat balanced meals throughout the day and 1/2 an hour before you go have a low calorie, high fiber snack like an apple, orange, yogurt and bran or small salad.
Mentally practice strategies for declining food offers. I've had some thank you they're delicious. I'm just taking a little break right now, everything looks just fabulous.
Have conversations away from the food table.
Nibble on healthier stuff - fruit, vegetables, turkey, pretzels, salsa, yogurt-based dips, popcorn, shrimp or prawns.
Portion Control - 3 handfuls of peanuts, about 4 oz contains 652 kcal, the average serving of cocktail meatballs = 160 calories, nut mix = 220 calories, nachos = 310 calories, crunch mix = 200 calories
Avoid the mentality "I've already blown it..." and practice moderation instead.
Get rid of your plate and napkin when full.
Have a mint or gum when you are finished eating to clear the taste from your mouth.
Stay hydrated. Hold a glass of water in your dominant hand. This way you will nibble less and drink less alcohol.
Watch the alcohol (to be covered on the 26th). 4 oz of eggnog and 1 1/2 oz of dark rum = 265 kcal. A couple of those is equal to one meal.
Keep up your exercise routine.
Don't deprive yourself the next day to compensate. Your body will go into starvation mode and your metabolism will plummet so your body can hoard nutrients.
If you are currently trying to achieve a healthy body weight, aim for weight maintenance through the holiday season instead of weight loss. This way you won't feel like a failure and you can get back on schedule come the New Year.