Having a plan is essential to avoid the one bite, two bite trap.
Many people set goals for the holiday perdiod (Thanksgiving to New Years) to simply "maintain." I think that is a good strategy.
But I'm still going to try to lose, though I've reduced my goal for the entire period to be losing 10lbs.
The tactics I use for individualdays/meals is the following.
1. Plate Distribution: I keep carb and fat portions to 20% each on the plate (of total calories). The remainig 60% of the plate is for lean protein and vegetables. I don't measure, I estimate.
2. Alcohol: I choose between alcohol OR dessert. If I choose alcohol, it's limited to 2 drinks. If red wine is available I drink that because it is the best alcohol for it's antioxidant value. Even a tiny bit of booze stops my weiight loss for a couple days (and makes me hungry) so usually I opt for a small serving of dessert instead. And I never drink more than once a week.
3. What to drink: I notice a lot of gatherings people seem to forget about non-alcoholic options so I bring my beverages of choice (diet cherry coke or even bottled water). This way I always have something I can drink and I'm less tempted to grab what's available.
3. Mental: Visions the holidays mostly include a turkey with all the trimmings (or some sort of food). I've tried to re-associate in my head instead to focus on the people I will be seeing. I set an intention for the event to catch up as much as possibe with people I've not seen for a while, and really find out how things are going (not just chit chat). Games are also wonderful distractions. Before I know it, I'm not thinking about food.