What I really mean is prepare for the times when you'll have down time at home, in between all the holiday cheer. This is a very important time to hone your healthy food shopping skills to make sure you're appropriately fortified. The key here is stay consistent in the most inconsistent time of the year.
I'm going to keep these things around: liquid egg whites, frozen (organic if possible) vegetables, ground white meat turkey, sweet potatoes, acorn squash, butternut squash (prepare the squash plain, the acorn and butternut taste awesome with just some black pepper especially when combined with the veggies and turkey or any other lean protein), brown rice (make 3-4 cups and keep it in a large tupperware in the fridge), organic low fat tomato sauce, and bbq sauce.
All the squashes can be prepared at once while you make the rice on the stove top, these carbs are very important to have around because the proteins take minutes and with these already prepared the meal is a no brainer. I like to use the tomato sauce or bbq to dress any of these meals.
Its also a good idea to eat a good, solid, clean meal before going out to any party or even dinner, I'll be less likely to overeat and can enjoy sampling all that's available without the desire to gorge myself which is always possible if I'm not prepared.
lastly, dont forget your long term goals, keep your eye on what you want to achieve and use this time of year as a reference point for getting through anything.