I always cooked yorkshires first , just make sure they are cooked to a dry consistency so they don't sink too much
I always cook beef and turkey for Christmas , and have been known to cook the beef the day before , cook it rare , then when completely cool , slice and a quick blast in microwave to warm through
If you are putting everything into dishes for guests to serve themselves , try to get serving dishes and plates as warm as possible , and split the elements into as many serving dishes as you can as it can descend into chaos when passing dishes round
Put the gravy out as hot as possible in as many jugs as you can find , and put it out last as at least that will keep the food warm
And as everyone has said Meat needs a long rest anyway , so parboil your potatoes , heat the oil in a saucepan first and put straight in oven
Dont over cater ! ( I always do ) , do a time plan for what needs to go in when to be ready by the time you want to dish up
Have a few drinks , expect something to go wrong , its not the end of the world
Get everyone to help clean up ....find the sprouts you forgot to put out
drink some more