Your business is located in a great area. Some options for you would be:
-Join a networking group for small business owners.
-Use your vehicle as part of your ad campaign (and yourself as well).
-Make some t-shirts, pens, water bottles with your logo and information and then distribute them to your current clients and also to various chiropractic offices, medical offices, massage places, etc.
-Donate some sessions to a local non-profit organization so they can use them as part of their silent auctions for fundraising.
-Place an ad on Craigslist (this has been very effective for me).
-Put up brochures/flyers at various coffee shops, athletic/sports stores.
-Join your area’s chamber of commerce.
-Have an open house once a month until you get really busy.
Some or all of the above methods could work for you, so you’ll have to decide which ones would be the most efficient for you. I hope this helps.
nothing to add to Harris’ list. It is very comprehensive.
I noticed on your profile, though, that your liability insurance is currently provided by your employer. If you have not already done so, it would be a good idea to set up a business and get your own liability insurance so that you can properly train clients outside of the gym/studio environment.
I would start with a really great client management software. I like www .fitify.me make sure you use one that will let you post your schedule so you can run your classes in multiple locations. Also having the ability to collect multiple forms of payment will help branding you into a legitimate business. Volunteer your services to help raise money for a cause you support, offer to teach a group class and have the charity collect the money. This will get the word out about your skills. Make sure you can organize and contact all those people that took your classes in the past. They you can do things like a message blast out to all your clients saying something like ‘you’re running a class in the park today’. I like Fitify cause they are really good to the little guy, they don’t cost much but they really bring legitimacy to any one person business like a personal trainer or palates, yoga & zumba instructor.