Oh and every year I go a bit mad in the after-Christmas sales, so this year I am definitely not buying any more cards, wrap, decorations etc. - I must use up some of my stash! 
Likewise, I will only get a few extra bits of choc for DD's stocking (choc coins, Lindt reindeer), as I've already stashed a load of stocking bits and mustn't buy any more.
I will also stock up early on wine and fizz for our own Xmas dinner, and try to prevent DH from going overboard with the extra bits, cheese etc. for Christmas day. We still have some quince paste and chutney in the cupboard that wasn't used last Christmas...
This year I'll also plan and book in pre-Christmas events as early as possible, and perhaps suggest that MIL's present to DD is a panto trip (I detest panto but DD loves it....last year I paid a huge amount for MIL to take DD to one, and then MIL also bought her a ton of quickly-broken plastic crap on top. Much easier all round for MIL just to pay for the panto and get her a selection box to open!)
We got a good quality free range chicken last year instead of turkey (DD still too young to notice or care), and that was much more manageable and much cheaper. Easy to then buy a lot of M&S ready-cook sides which were lovely. But I must remember that we ate so much we didn't manage the pudding until about a week later!
Finally, I will make every effort not to get ill this year. I nearly always celebrate Christmas with my annual Christmas cold or flu. Last year I woke up on Christmas day with the start of that 3-week cold that was going around the whole country (the one the Queen had....I'm fancy like that
) and I felt grim until well past New Year (it turned into a chest infection). This year I am going to shovel vitamins in and eat mountains of kale and veg as Christmas approaches in an effort to ward off the bugs.