I'll sit down on January 1st and plan 12 projects, one per month (while I watch football). The ones done early in the year are responses to events I know about (babies coming, housewarmings, weddings etc.), and some will be Christmas gifts with a deadline of October 31st. During the year there will be new priorities and a few of the first 12 might not get done at all. I'll do more than 12 projects in the year, but I plan so the most difficult will be done first. I do this also because I get more work done in the winter than the summer.
I don't allow myself to spend the week before Christmas pulling out all the stops and losing sleep to get things done. I'm not at my best during family gatherings unless I've had decent sleep. So in March I'll pull out Christmas fabric and make a start on those "Ohmigosh I need a gift in a hurry cos I forgot someone", and I'll have some other large non-Christmas projects underway.
By the time the end of the year rolls around, I'm working on UFO's that don't have a deadline so I can put it all away when I need to without feeling pressured to finish.