1. Be recognizable
    "Who are you supposed to be?" Don't be so obscure that very 5 minutes you have to explain your costume. Ghostbusters > Ronnie Dobbs
  2. Dress for the weather
    The slutty pumpkin outfit was a good idea when you thought of it in July, now it's Halloween and its 40 degrees out. Should have been chewbacca instead.
  3. Accessibility means booze
    Nice Day of the Dead costume. Too bad you have to take the head off every time you take a sip of beer. Need to go the bathroom? Good luck. Maybe your GF will hold your entire costume all night.
  4. Be original, not just slutty
    So help me god if I see one more woman dressed as a kitten, angel or devil, I'm going to shoot somebody. Or worse yet, you're just wearing a slutty outfit from your closet. Being slutty is great and all, just be slutty and creative.