From the POV of a seasoned Christmas dinner cook (keeping it relatively simple...)
Adult (late) breakfast, bagels with smoked salmon/cream cheese, satsumas, grapes, etc. Probably also cold gammon, baked the day before.
Children’s earlier breakfast, whatever they like best - in Gdcs’ case, probably Nutella pancakes.
Buck’s Fizz on tap (or what anyone else wants) from right after breakfast until dinner, which in this house will be around 5. Any children will be given something simple at their usual lunchtime.
Usually a walk in the park between breakfast and dinner
No starter, but fairly substantial canapés (M&S’s best) at around 2-3, to keep everyone going. Usually fishy rather than meaty.
Dinner - turkey brought to the table in all its golden glory - no plating up in the kitchen here, thanks.
Lots of crispy roast potatoes, roast parsnips, carrots and lightly cooked sprouts (we all like them).
Lots of home made pigs in blankets, made with best quality sausages cut into thirds and streaky bacon. (Made and frozen in advance).
Lots of proper turkey gravy, made in the roasting tin after the turkey was taken out to rest, using stock made from simmering the giblets the day before.
Home made pork sausage meat, sage and onion stuffing. Also made and frozen in advance.
Home made cranberry sauce, made in advance.
Homemade Christmas pud, lights off before bringing it flaming to the table.
Lots of brandy butter, made in advance.
A dessert wine, for anyone not too pissed already.
Cream for those who want it.
Cheeseboard, fruit and mince pies, though everybody’s usually too full.
Coffee and brandy/liqueurs - for anyone who wants them.
General collapse on sofas.
Anyone who’s peckish later (unlikely) can pick at cold turkey/gammon, etc.