When dealing with the supernatural, it's best to go boho.
Horror films often have a bad enough reputation as it is. When it comes to style in horror films... Wait, does such a thing even exist?
It really doesn't, I suppose, because fashion and terror are hardly ever connected. What we are supposed to experience when watching a scary film (besides being scared), is being able to relate to the "every woman" protagonist, so that we can feel her fear. But is the "every woman" often just a casual dresser as she is depicted in most scary films? Do scary things not happen when you're well-dressed?
Apparently, if it involves ghosts, then yes.
The Skeleton Key (2005) does a pretty good job at combining casual and chic. Although Caroline Ellis (Kate Hudson), a hospice nurse who works at a plantation home in New Orleans, may seemingly not consider her "look" when getting dressed to care for an elderly man, she must subconsciously adapt to her environment. She deals with Hoodoo ghosts. What does this translate to, style-wise? Dark-boho-chic.
Costume designer Louise Frogley, though not necessarily a legend, has worked on the likes of Iron Man 3 (2013), Ocean's Thirteen (2007), The Rules of Attraction (2002), Traffic (2000), and countless others.
This is definitely a look to aspire to.