I think just keep in mind that finding a sub isn't like posting on Craigslist for a secondhand TV...there are real people with real feelings who want to make a connection on several levels. Introduce yourself, your interests (not just bdsm stuff...what do you do with your spare time? What's your career field? What do you like in a partner?) and maybe even give a "sample" -- what exactly you're looking to do (again, not just a word or two of things you like, but how you'll control, what scenarios they'll endure, how often you want to play) or a description of some (real!!!) scenarios you've done in the past (doesn't need to be dripping fiction: just a factual account of what you've enjoyed, so they'll know what to expect).

Hope that helps!