, get a hair band, a string one not a thick one, and get flat shoes dont wear any bling besides earings and even then dont pick the stand out earings wear studs. paint your nails black and dont wear too much make up. rachel tends to go for the more natural look.
I think you should buy the People magazine titled Glee. In there, you can find a how to get Rachel Berry's style tip thingy. It tells you cheap alternatives to help you look like Rachel.