Here are some easy Halloween costume ideas that can be put together quickly with minimal effort:

• Cowgirl: Flannel shirt, jeans, cowboy hat or any boots.
• Risky Business: White button-up shirt, socks, no pants needed.
• Wednesday Addams: Black dress, black thigh-high socks, white collared shirt underneath, braided hair, and dark makeup.
• Hippie: Tie-dye shirt, flowers in hair, colored sunglasses.
• Harry Potter: Black skirt, white shirt, tie, and glasses.
• Sailor: White pants or skirt, striped shirt, sailor hat.
• Cat: Any outfit with cat ears and makeup whiskers.
• Greaser: Black leggings, black shirt, red lipstick.
• Rosie the Riveter: Jeans, red bandana.

Other quick ideas include a cat burglar, Power Ranger (mask + solid color clothes), skeleton, unicorn (headband), cereal killer (pun costume), and a lumberjack (plaid shirt and fake axe). These ideas require very basic items, some even from regular closet staples, and are excellent for last-minute costumes.