Of course you can always resort to the obligatory Psycho homage. This $5 bathroom makeover doesn't require much more than a black sharpie and some acrylic paint. If that sounds like too much work, you can just buy the shower curtain here.
This bloody curtain and math mat set brings to mind the bathroom scene from The Conversation.
But really, if you want to scare yourself at 2 a.m., I think this Nosferatu curtain is the way to go.
After inviting a killer to your shower, it's probably a good idea to bring in The Enforcer.
Finally, your sweetest option is probably this Singin' in the Rain curtain (available at fredflare.com).
