In 2007, I came up with the idea of a "split-personality" costume for a contest at my high school. In 2010, I decided to revamp the costume for Halloween! While this site won't teach you how to sew, it should give you the basics for putting together a similar costume, from clothing, to makeup, to variations for guys and people who don't sew.
The costume is a caricature of split personalities, of course. People who suffer from true "split personalities" are diagnosed with dissociative identity disorder (also known as multiple personality disorder). You can find out more information about it by checking out the link on the sidebar.
I absolutely love making costumes and getting feedback, so feel free to send me your ideas or results!
You can contact me by e-mail here.