When our now three year old was born, my wife started a great Christmas tradition. Each year, we go out and my son gets to pick an ornmanet for the Christmas Tree. We put the date on the back and then let him hang it on the tree. This year, we each picked an ornament, so that was different.
The great idea my wife has about this is that when our boy is old enough to be on his own, we will give him the ornaments, so he has some to start with. My wife got this idea from her mom that started this tradition. To this day, we have little ornaments that my wife had on her tree when she was a little girl.
Share any traditions you may have!