Using multiple methods has worked great for my studio so far. A website linked to your social network sites (facebook, blog,..) and craigslist ads are a good start, but nothing beats meeting people face to face and showing value in your service. So, local chamber of commerce meetings, networking with physical therapists, other trainers, or people in grocery stores. Depending on your studio location, having a street-visible sign, tall flags, and windows so people can see what’s going on inside helps. People are naturally curious. Hope this helps and best of luck to you in business!