First Sunday in Advent (29th Nov this year) we go to a German friend's house where she makes an absolutely HUGE brunch. Fantastic German tradition. There will be, let's see, about 8-10 adults, 2 children (ages 4 this year) and some dogs. It's enormous fun, really relaxing and a great start to the Christmas period.
I'm an expat, and the only slightly-expatty thing I do all year is go to a Christmas Fair run by the Brits down the coast. They have a Santa, games (fishing for ducks, etc), tombola. I can buy UK food I can't get hold of here - mince meat, giant tube of Smarties, oxo, stuffing etc. Tha's usually the beginning of December.
Tree goes up on 8th Dec, it's a holiday here so we can all chip in. The Christmas CD goes on, DH wanders off shaking his head, me and DS decorate. DS has a silly cheap tree in a pot that I bought for about a fiver last year, with some 75p baubles and silly beads, he has that in his room and can play with it til his heart's content, although I do put non-breakable stuff on the main tree at child height and I'm not so precious if I come downstairs from a wee and find the felt reindeer is being arrested by the Playmobil police!
Christmas Eve we go for a wander round a tiny town near us: cobbled pedestrianised streets, hot chocolate, look at the lights. Last year they had a live nativity in the church garden (not a graveyard!). Cute goats. We buy takeaway roast chicken in town and have that for dinner. No preparing and washing up is minimal.
When home, we do dinner and bath, then we have a caga tio caga tio a Catalan log with a smiley face that you feed and cover with a blanket. You then beat him with a stick while singing a song (about poo) and he poos small gifts and chocolate! This year he will poo a couple of Mr Men books and Polar Express dvd which we'll watch that evening. (Caga tio is closely related to the yule log in that he comes down from the mountain and stays in your house for all the festival). Oh, the Caga Tio arrives the day we decorate. We sneak him outside the front door, then make a knocking sound so DS find him! It's the same log every year, and a firm favourite Christmas thing.
DS brings his stocking into our bed, usually to ask us to help open his chocolate coin (he was just-3 last year). We open presents after breakfast, so put something Playmobil-esque in his stocking to help keep him entertained, just a small thing.
Christmas Day breakfast is made by DH, something of his choosing.
We open presents after breakfast, then take it in turns to shower and get dressed. We usually wear something fancy/pretty/ironed.
Christmas lunch is made mostly by me, but DH also has a hand in it. We have FIL, BIL and SIL for a late lunch (all single, all lovely) around 4pm. Not much traditional food as I'm a lousy cook, we can't find the right potatoes for roasting, I can't be arsed to roast a chicken, hate turkey.... and so on! Last year was salmon for FIL, something meaty for the rest of us, mash, stuffing, cranberry sauce, mince pies, pigs in blankets, random veg. I think we even had stuffed vol-au-vents for starters - very 70s. I make mince pies. No one eats Christmas cake except me, so I don't bother any more (my English friend makes it for her Catalan in-laws and they call it El Borracho - the drunk one!). SIL brings pudding - tiramisu last year.
We all go for a country walk after lunch, although it gets a bit dark - DS got the IKEA wind-up torch last year, great present! Still loves it. 4€ 
We'll probably watch Polar Express again and lie on the sofa with our trousers open 
Boxing Day is either us to a friend's house, or them to us. More food, very relaxing, some games with their DC and ours.
6th January is celebrated here with the 3 Kings arriving in the port and doing a procession through town to the main square, all the while flinging boiled streets to the children in the crowds. Then people go home to a nice meal and to open presents the Kings have brought. Some Catalans (and Spanish, actually) only celebrate Kings, not FC. Or they'll do toy gifts on 25/12, clothes/stationery/books on 6/1. Oh, and 24/12 is bigger than 25/12 for some.
So, DS celebrates: birthday in December, Caga Tio 24th, Christmas Day 25th, Kings Day 6th January. Then NOTHING for the rest of the year! Poor bugger! Really though, Caga tio, Christmas stocking and Kings Day gifts will be small - Caga Tio is perhaps like a Christmas Hamper; albeit a hamper you don't hit with a stick 
I love Christmas