Themes. But that goes for almost all of my parties! But every birthday party we have has some theme or another. Our last was my boyfriends 21st and the theme was Margaritaville. It was great! We had a cake shaped like a salt shaker and tropical decorations and margaritas and daiquiris. Our next party is 2 of our friends 21st that we are combining into 1 party. And its gonna be a toga party