Word of mouth is the best advertisement but you also want to let people know what you do and that you are available.
I looked at your profile and saw that you carry you own liability insurance. That is great. I assume that you also have registered your own business and that you are in compliance with all the rules of the state you live in.
I recommend that you have a few shirts that carry your company name (or your own name) and contact information. Wear it wherever you go, and also put a decal on your car. Never leave your home without business cards.
When you first begin with in-home training, you will be tempted to accept any time and any location. This can lead to a lot of running around and inefficiency for you.
I also recommend that you should be mindful that – wherever you go – you are always an advertisement for yourself. That also includes places like Twitter and Facebook.