My unofficial rule is 'no repeats', at least not within 1 or 2 years. So last year I did a venison wellington... so no wellington this year. Nor poultry leg confit.
Regarding dish selection... most of my family aren't big eaters, so the priority is to try and keep the individual dishes somewhat light, while still keeping them interesting. But I try to stay away from the really heavy stuff.
I also found out that logistically it's actually a lot easier to do more smaller courses instead of fewer bigger ones. It's easier to do 5 small courses than 3 big ones IMO. Also makes it easier to keep the whole menu more varied and 'satisfy everyone'.
Another factor is 'stuff thats easy to prep ahead and somewhat foolproof'. In the end the whole point of holidays is to be with family and the last thing I want is to have a stressful evening where things can go wrong. So stuff where you can prep ahead on the day before is really my go-to. I'll also try to avoid doing dishes I've never made or tested before.
To keep it light the easiest thing to do is to cut down on the starches and basically make all the dishes a combination of a protein + a fruit/vegetable element. And then you just work down the list of the main proteins.
So last year we had some... filled zucchini concoction with some guineafowl (but really it was a vegetable dish), we had spanish style garlic gambas with some roasted peppers, bruscettas and basil, a pheasant leg confit with some pears in PX/thyme sauce, a venison wellington with pumpkin puree and some assorted vegetables, and then dessert; lime pie, mango panna cotta and coconut cream.
Probably the best meal I ever did on my own yet it was a complete cakewalk on the actual night itself because much was prepped ahead. Each individual meal was really easy to tackle because it was just 2-3 elements, and when you limit yourself on the portion size you can still keep it really light because there's no big fillers like mashed potatoes, cream sauces or big piles of pasta. The last thing I'd serve on a christmas night is something like a carbonara.
This year we split it up a bit - I'm not the only one in the family who likes to cook so that simplifies things but we still tried to make a nice spread of dishes. Only took a little bit of coordination to make sure it resulted in a decent menu where dishes didn't overlap too much. Really worth considering if you have people who like to / can cook because it takes work off your plate while people are often happy to help.
So we'll have some vegetable soup, a river shrimp thing with ras el hanout sauce and sea vegetable, a guineafowl roulade with raspberry sauce and a fennel, spinache, pear & mango salad, a venison with blackberry port sauce and oven roasted veggies, and then dessert. But it's all going to be a cakewalk because anything that actually takes work can be done ahead by different people, so on the day itself it'll just be some heating / cooking and cutting the veggies for salads.
