Soft play areas is where I used to let my DC run off the excess energy and excitement. They can still behave like feral kids there, but it's soooo much easier and nicer than a cold park.
I also had a little gizmo, it was a little plastic dome with a flashing red light inside. I used to put it in whatever room they were in and also take it with me outside. I told my DC that it was Santa's secret camera and it was recording them to see if they had been naughty or nice.
I only had to remind them that Santa was watching whenever their behaviour deteriorated, and that would usually get them back in line.
There's also a really cool online Santa site where you can add your kids name, pics and info and whether they had been naughty/ nice this year, then an email is sent showing Santa ''looking up'' your DC and they can see their own picture and info etc A couple of times I did these, saying they were being naughty, and it improved their behaviour immediately ! ( of course I then did this again, a few days later, saying they were good).
My DC were also very into arts/ crafts etc, and we would spend days making/ painting baubles etc ( you get really good stuff online eg make an angel kit or make a bauble kit), as well as making reindeer food (oats with glitter) and cookies etc. Anything to keep them busy really.
Oh, and when they're really grumpy, I used to put on Xmas music quite loud and sing along so they couldn't fight with each other as they were too distracted by my awful singing - they used to crack up at this !- :)
Basically the whole house had glitter and poster paint everywhere, and they knew all the words to every Xmas song, but the DC had a great time and have fond memories of past Xmas's :)
Just try to remember how HUGE Xmas is when you're a kid, and