I've read recently of the one about your children having new PJs on Christmas Eve and love that.
We buy a new Christmas tree decoration each year for DS and will do the same next Christmas for DB. They'll be able to choose or make something as they get bigger and it's going to be lovely seeing them decorate the tree when they're bigger with decorations that have history. Tree might look shocking though
So what else? I'm sure I read something on here about leaving a bit of sprinkled glitter and telling your children it's magic dust to help reindeer fly or something?