For us Christmas starts the first weekend when the village lights go on (and there is a little celebration for that). The day before I take the children to the village Christmas shop to choose a new decoration - they choose one new one a year. On the sat, the tree is purchased and we go to the light ceremony and then have drinks with friends.
Decorating the room is a family affair with hot choc (and baileys for the grown ups), Christmas music. I do the tree and the children decorate the room.
One present per person is placed under the tree and you can touch, sniff it etc. each day you make one guess as to what the present is - if you guess correctly, you get to open the present, if not you put it back until the next day. Presents are of course disguised and guesses have to be specific. Cd wouldn't be good enough - it would have to be 'the new now album'. In 35 years of doing this, I have never correctly guessed. But it all adds to the excitement and my girls live it.
Also, in the run up to Christmas, the girls will make a Christmas decoration or present for family - something like a little calendar. Yellow moon have nice Christmas activities which are not too tacky.
Then we have our day Christmas shopping. Usually go to Milton Keynes as they have got a crèche, but now that's gone I'm not sure. I always go for either the day or the weekend and take the girls, and my mum and we see FC, the Xmas decorations and so on... This has become a mini tradition in its own right as the girls are given money and this is when they buy their presents. At 7 and 4, they really like this tradition as wehave some good girlie time 
Christmas Eve, we always have people over in the evening and a mini party to start Christmas off. This includes a small tree present (which includes pjs for the children) and children put out the oats for the reindeer, leave out Santa's key and so on....
On Christmas morning when the girls wake, they bring their sacks into our room and open their presents from FC.
Then shower, get dressed and we all have a special breakfast. Usually pancakes and bucks fizz / OJ.
Then when tidy we open presents from us (under the tree). After this the girls have time to play with their toys in the morning whilst we tidy up all the mess.
Then we go to my parents for lunch. We open presents from my parents after lunch, and again the children have time to play with their toys etc.
Then we have a buffet tea and we open presents from other family members. After we all play a game together. This usually includes chocolate roulette - which the girls love! Tv is banned on Christmas day, as is spending the day on your own. It's a family day and we all celebrate together.
Also, in the presents is a joke present which has clues in. You are not allowed to open that present until you know what it is. Sometimes it has taken me all day to work it out!
The next day we come home and there will be a few presents left under the tree from other people and we open those.
Boxing day is the day we spend alone as a family (just the four of us). We have a movie in the afternoon, and play a game together in the evening with the children.
Then each evening, we'll invite a different set of friends over / go to family - each night is a mini party. The children dress up / swap presents and we all play games / socialise. If its a family that we don't do big presents with, then there will be little 'tree presents' under the tree for the children. This is usually bargains I've picked up over the course of the year - for example a bag of marbles for 50p etc. nothing big, but just a little something.
New year - see friends and party.
Christmas finally ends in our house on new year's day when we take the children to the Panto with family and then have a curry afterwards.
The next day the tree comes down.
Christmas is epic in our house and my children are excited already!