How should I style my hair?

Tomorrow is my school dance and although Im not really looking to go all out on hair style Im not sure what to do with my hair. I have long brown hair (It reaches to my bust line) and it curls and straigtens fairly easily. Its naturally just wavy frizzy weirdness when I let it air dry, but it's straighter when I blow dry it. I don't think I want to put it up.. But I don't care. And i dont know if this matters but my dress is a casual navy blue and white polka dotted dress. It's got cloth buttons up the chest so my look is pretty casual. Thanks!