I also buy my kids an ornament every year and just realized my oldest is a college freshman and should I stop now? Haven't bought her one yet, LOL!
One of our favorite family traditions is to camp out in the living room in front of the Christmas tree one night before Christmas (NOT Christmas Eve!) We read kids' Christmas books and as they got older, played board games and re-read the most favorite Christmas books every year. They usually get to open their ornament present from us this night, or it is also fun to give them pajama's that they get to open and wear on this night, too! Either or both! They love this tradition and even my college freshman will join us (although she usually asks to get to sleep on the couch!) Now that we are older, we use blow up air mattresses.
Another tradition that a friend started for Christmas. Our second child received a fancy Italian beginner nativity set at his birth, it just had the manger, Mary, Joseph, angel and baby Jesus. We buy him an addition to his set every Christmas, like a shepherd, sheep, wise man, camel, etc. every year at Christmas to complete his set. When his older sister got to be about 8 years old, she asked for one, too, so we are playing catch up with hers to get everything complete! This year one child asked for a dog and one for a set of chickens, LOL!
Take only photographs, leave only footprints.