Since I like Mickey's b-day theme and Halloween costume to coordinate I went with a jungle themed b-day to go with his lion costume. Last year he had a cowboy themed b-day and he was a cow for Halloween. And we had OSU themed pennants and matching shirts and a onesie that said "Team Hettwer 2006" in the delivery room and then he was an OSU pumpkin for Halloween.
Not sure why I like them to coordinate. Maybe it's because it helps me narrow down the choices. Or, maybe because I'm so planning a really awesome mini album about it! Hah!