Any ideas on how to organize my business?

I have went out to peoples homes & offices for years to help them get organized. I have also done this work over the phone & it has actually worked out very well. I guess it would be as if I am consulting them. I would like to make the phone consultations a bigger part of my business & I only need about 10 hours of work a week. I have never adverstised. What would be the best way to get new customers so I always have this 10 hours of work a week? I know people who do the work I do charge much more than I do. I charge $50 an hour & now that I am going to do this over the phone it doesn't matter where my clients live. How can I let them know about my business? I live about an hour away from D.C. & the outskirts of D.C. in Maryland I know there are huges houses in Montgomery County, MD so should I just go to their grocery stories & put my business card on their boards? Any ideas? thank you.