Yeah I hear you, I usually do some sort of fermentable beverage like a year old apfelwine along with my Jamaican Banana Bread
made with homebrew Banana wine and rum as x-mas gifts myself.
And I too have done the "Don't open til........" labels as well. I even have special hanging labels for gift bottles here.
There really are two types of holiday beers, heavy ones like barleywines and winter warmers. Thick heavy beers that take awile to brew, the other category is a spiced white (wit) beer. A wheat based beer, usually done with beligian yeast and spiced with all sorts of spices.
Cinnamon, nutmeg, clove, allspice, ginger. citrus peel....even some of the "odder" spices work well in those blends, like cardamom or coriander.
Also dark fruits are common, figs, dates, plums, also pumpkin, sweet potato, cranberries....Heck even organic mince meat might be interesting (Just make sure it doesn't contain suet or fat.)
Think about the desserts and foods available at this time of year, and those are the flavors that you can work into a good base beer.
You basically need to find a nice simple wit or belgian blonde base and then flavor it with the afore mentioned spices
If you look at my pulldown, I have a Leffe Blonde clone that you could possibly use as a base with lets say a dark fruit like figs, and some spices. Or you could look for one of the hoegaarden clones on here or online (or blue moon of any wit beer, I think Biermuncher has one called blue balls that might work) and spice it with orange peel, coriander, cinnamon, cloves, ginger and nuthmed.