I have a few ideas floating around, I still haven't been able to pinpoint one. First of all, what many could consider the "underbelly" of most of the Western world: Roma, gypsies, wanderers. Around the 1800-1900s many settled in what has now become Black Patch Park, in Smethwick (right at the edge of Birmingham). Another is burlesque shows and particularly Dr. Sketchy's Anti-Art School where you can do life drawing with burlesque dancers as models. And my third idea is just looking at people waiting outside of clubs, you get some pretty weird characters.