Party themes really depend on where you are. In the country a western style, in the City do a night in Paris sort of thing. Also if you are having trouble you can theme a party after a favorite...
Teens aren't usually one's who like to have a theme. Teens also want to be grown up so pick an adult party like Marti Gras or some other and just make it at little more PG rated. You can have all the...
You can throw a party at home, and invite friends to go to your house and play games/ hang out. You can go bowling, or go to the park and play something such as basketball, volleyball, soccer, etc....