Normally, I have to go to work in the morning (or take a whole day's leave) and DD comes with me. DH used to have coffee on the shopping street near me and meet us later. Now though, he is supposed to work on 24th as well (or take a full day's leave) - and he works near home rather than in town (I am city centre). But that used to be followed by buying DD's birthday cake in M&S and getting any other small bits we wanted, and lunch in town before heading home.
The other thing that changed last year was we did a Christmas Eve swim for the first time - that may be on the Sunday this year, or 24th, we don't know yet - but it was great fun! Cold, but hot showers after, and mulled wine and chat for a while before everyone went their own ways for Christmas.
Once we get home, DD bakes cookies for Santa, and DH and I do prep work for Christmas dinner - peel veg, make stuffing, DH rings DMIL to remind him how to cook sausage meat....
We have a "platter" dinner, cured and cooked meats, cooked and smoked fish and shellfish, cherry tomatoes, olives, cheese, pepper and carrot sticks, hummus, pate, crackers or naice bread, ...a mix of nice things that everyone likes to pick at.
DD (as the youngest) lights the Christmas candle, to show that there is "Room in our Inn" for weary travelers, and we remember the good and bad things about the year just finishing.
Then we get out the Christmas Eve Hamper (see other posts on relevant threads) and DD sets up her stocking and snack for Santa, before going for a festive bath and into new cosy PJs. She comes back down for a hot chocolate, and then we read "Twas the Night Before Christmas" in bed to her (and maybe another story too) - she's mostly gone past bedtime stories but it still seems to be an important Christmas tradition for her.
Then DH and I relax, and aim for an early night ourselves as the run up to Christmas is always mad busy, so we are shattered!