It's hard to think of them off the top of my head, but we like to do silly stuff like that. Tomorrow we're having an elaborate "birthday" party for DS's hamster, for example. The kids spent the morning making cards and decorations for it.
It's pretty much an excuse to get me to make cupcakes, but that's fine with me!
And last week DS and I filled up 50 water balloons (it was supposed to be 100 but my fingers couldn't take any more tying) while DH was at work and surprised him with a "water park" in the backyard when he got home.
I guess those aren't really traditions in that they aren't things we do on the same day every year or anything, but they do make the day feel special somehow!