All of my submissive partners have been men I've met for the first time in a vanilla setting, who had no idea of my kinks. If I had good chemistry with them, it was due to my attraction to their nature (submissive/polite/service-oriented), so the kinky dynamic just came naturally. I'd suggest not looking for dominant women specifically, just look for women you vibe with. Many Dommes wont post to those forums in fear of being used as a kink dispenser.