Halloween costume for a 12 year old girl???

It has to be something I can wear to my junior high. Also, I want it to reflect my interests: music, (50 cent, KanYe West, Akon, Britney Spears, P!nk, Gwen Stefani, Avril Lavigne, ect.) dancing, (I do ballet) shopping, (I'm really into Abercrombie, American Eagle and such.) and I'm kind of known as a bit of a "Paris Hilton" type if you know what I mean.