The Inspiration: Jackie-O in The House of Yes
Essential Elements: Pink Jackie-O-style coat with black trim and lapels. Pink skirt. Pink pillbox hat. Basically your standard Jacqueline Kennedy costume, only much crazier.
Key Accessories: Gun. Pills. Someone to play your brother who you could also try to make out with.
The Attitude: Out of your mind. Dramatic. Untethered to reality. Suspicious of outsiders. American royalty with absolutely no cause for it.

The Inspiration: Libby Mae Brown in Waiting For Guffman
Essential Elements: Polo shirt, preferably in some sort of garish color combination. Visor with the Dairy Queen logo on it. Nametag. Gum.
Key Accessories: Some kind of fountain beverage. A cigarette. Advanced-level costumers might opt for a charcoal grill and an unadorned piece of chicken.
The Attitude: Low-key. No, lower. Even lower than that. Dreaming of a better life, but reeeeally languid about going for it.

The Inspiration: Mary in Party Girl
Essential Elements: Sensible white blouse with a high neckline, preferably with some kind of bow. Short red skirt. Red fishnet stockings. Leopard-print fur coat with unnaturally wide lapels. Red gloves. Round-spectacle sunglasses.
Key Accessories: Tiny, fashionable purse. Maybe a library book or two (categorized by the Dewey Decimal System, of course). A small army of neon-fashioned '90s hipsters.
The Attitude: Over-the-top. Entitled. Kind of bored with the party scene.

The Inspiration: Meg Swan in Best In Show
Essential Elements: Adult braces. The single most severe bob wig that's available in the costume shop. Power-bitch business attire.
Key Accessories: Busy Bee, obviously. Do not even think for one second about showing up without that Busy Bee. (Not acceptable: plush fish with black and yellow stripes.) A jittery Weimaraner. Cup of coffee obtained from a Starbucks across the street from another Starbucks.
The Attitude: Constantly on edge. Aggressive. Competitive. Kind of stand-offish around dogs.