Word of Mouth is great! Start with your friends, family..make up some promo materials by using a cheap resource such as www.vistaprint.com. You can bring those materials (business cards, promo post cards, etc) to local schools-leave in their break rooms for the staff members, library bulletin boards, grocery store bulletin boards, email blasts, online posts. Also think about leading small group sessions-maybe contact a local women’s group (or even a church group). Give them a free trial, show em what your all about.
Once you rope in 1-3 people and are successful you should be able to find new avenues to get the word out.