Hmmm, looking at your picture and assessing your 'vibes' (hehe) I immediately thought Edie Sedgwick, Andy Warhol's famously favorite model and actress in his Factory. I've been her for Halloween and it was SO fun - I felt so glamorous yet original, and not a carbon copy of the other 15 Marilyn Monroes around.
Part your hair to the side, tuck both behind your ears and then maybe bun it back so it appears as though you have a short haircut. Use liquid eyeliner on your top lid that extends to your outer creases, fill in your eyebrows with a dark pencil and make yourself a mole on your right cheek (and yes, it IS possible to do this quite tastefully... I think I looked hotter than ever with my eyebrows a little fuller). And an extra zinger would be fake eyelashes! And always keep your lips NUDE.
For clothes, simply black leggings, some sort of black wedge heels or high heel boots are perfect. For a top, Edie was known for making the sailor shirt very fashionable (simple tee shirt with dark stripes... you know.)
Or just any chic '60s close-hugging top or tank would do.
The icing on the cake... HUGE earrings!!!!
Here are some pictures for you to get an idea:
http://frillr.com/files/images/Edie-Sedgwick--'Chic'-Look.preview.jpg
http://xs128.xs.to/xs128/08235/7582_...ick2_1_618.jpg
http://www.observer.com/files/imagec...-EdieSed1V.jpg
Have fun, no matter what you go as!