I was approached by someone who wanted to take pictures of me, because I was ( i think) his body type, and present a very powerful persona. After 10 days of email flirting, and an hour or so of taking pix, he knew I was a sub, even if I didn't (yet). Huh. I suspect he knew almost immidiatly after we began exchanging emails, now that I think about it. ;p

We met entirely outside of the BDSM scene as well.

I don't know where you are or your age, but here are some suggestions if you are looking outside whatever 'scene' is in your area: Find someone you are drawn to. ask simple but open ended questions. Flirting is a great way to break the ice, especially as if you push a potential boundary you aren't locked into having outed yourself, if you desire not to at first.