My DC are teens now (they'll be 17 and 14.6 by Christmas) but when they were little we did:
Traditionally we have our main meal at lunchtime (always fish fingers/fish for DC and visitors, vegetarian grills for DH and I, lots of chips, salad, breads then pudding (trifle, ice-cream)
I do a late night buffet (French breads, cold meat/Quorn, dips, crisps, cakes, ) about 10-11pm.
After lunch, we went out to feed the geese at a local lake , or reindeer at a visitor centre (though they're stuffed to the gills so not bovvered
).
And before we left the house, I just had to "check the back door was locked" and put the Christmas Eve Hampers by the fireplace - aka The Elves pop round while we're out.
We did go to Panto when they were little, I tried to make it the night before my DParents came down, so they'd sleep in, and when they woke up, Gran and Grandad were here 
They always used to dress up after their walk (Fancy Dress) to watch TV.
Now, it's changed (of course)
We still do the Christmas Eve Hamper.
I take DD to ballet , usually mid December
Last year we went to London on the 23rd, it was great, not too busy and we didn't need to buy anything, just a wander. We're doing that again this year.
I've taken them to the cinema on Christmas Eve if there's anything on that's Christmassy.
I think Christmas Eve is a nice quiet day, in anticipation of the Big Day. Unless I had to visit people, I wouldn't want to be driving round.
We used to try to do things behind the DC backs so it all went seamlessly and magically (not now though, they can't be tricked)
DH and I booked a day off when they were at school, so we could go shopping.
DH took them to the cinema one evening (about the 22nd) so I could shop in peace with my Sainsburys Rewards and get the big food shop.
We took them to London to see the lights (no shopping)
I save £2 in a tin all year so we cash it up and each person has to buy themselves a random thing (DS likes to save his money )
I do feel
when I see parents and infant school aged DC, they still Believe.