Like Grease? Go as a Pink Lady! To imitate Betty Rizzo's look, throw on a collared shirt, a pencil skirt, a black scarf for your neck and a shiny pink jacket. You can wear black heels but I decided to wear black tennis and white socks for that '60s look.
Like Archer? Be Lana Kane! All you'll need is a sweater dress with long sleeves and a turtleneck. Accessorize that with a belt and finish the look with thigh-high boots. If you want to look more as a spy agent, throw on a backpack and put some fake toy guns on the side.
Smells like teen spirit! Go as Kurt Cobain (or any musician from the grunge era). Put on an oversized sweater (and a collared shirt underneath if you want), some jeans and sneakers. Optional, you can mess up your hair to give yourself that I-don't-care-about-anything look. (I overdid it with mine...)
Hocus pocus! Be a wicked witch! Wear a long, black dress with a black cardigan, black tights and black boots. Just wear a lot of black! And don't forget to top it off with a dark, wide brim hat.
Last but not least, if you are a fan of Marvel Comics, especially Suicide Squad, you could go as Harley Quinn (or in my case, a bootleg version of Harley Quinn). Just put on a baseball tee, some short-shorts, a choker, and some crazy boots. If you have long hair, put it into two ponytails. To look more like Harley, apply some fishnet stockings, a bomber, some spiky bracelets, fingerless gloves and a baseball bat. Don't forget to do your makeup like hers!