We do what most would consider Christmas dinner more or less every Sunday.
Joint
Pigs in blankets
Stuffing
Cauliflower cheese (Home made)
Roast pots (done with semolina and parmesan)
Parsnips
Yorkshires (Home made)
Sprouts
Carrott and swede mash (Aunt bessies)
2 x veg
I do bread sauce some weeks no matter the joint because I like it so why not. Don't get hung up on whether you should or shouldn't have certain items with the meat your cooking, cook what you like :) We like some of everything in proportion.
My tips, don't put pressure on to be sat down to eat at a specific time. I always let guests know it will be sort of within an hour slot ;)
Start with an empty dishwasher and sink, clean as you go and where you can re-use stuff after giving them a wash.
Double check everything will fit in the oven (I have some issues with this most weeks and it can take some logistics depending how many I am feeding)
Open a bottle of your favourite wine.
Your kitchen, your rules, if you want space and everyone out then off they go. Personally we are open plan so everyone sits up at the breakfast bar and we all chat whilst I cook. If they don't like my chaos and mess they can cook their own food ;)
I try and have cheese board, grapes pickles etc laid out ready and covered up plus an easy to serve pudding with custard/cream etc ready to go in nice jugs so once the main meal is done I can relax. I also get all crockery and cutlery out ready and put to one side.
Candle light and fairy lights make an atmosphere, as does a nicely laid table.
Napkins are not optional!
Delegate, I like to do all the cooking but try to aim for cleaning up with one person clearing the table, one scraping and rinsing and one loading the dishwasher, sides wiped down, leftovers in fridge etc.
Keep the left overs, next day bubble and squeak with cold meat and cheese and pickles is awesome. We chop all the veg, stuffing, pigs in blankets and pots and sort of mush together like a stuffing texture but with discernible bits still, then fry or oven bake till piping hot and golden/crisp. Really lovely, esp with brown sauce if not doing cheese etc.
All that being said, as I do this most Sundays I have treated myself to a M&S Christmas dinner so I can chill drinking champagne, so thats always an option ;)