I don't do commercial, but I do residential, and I figure my tactics are pretty much the same.
If I have a customer on a specific street, and even if I don't, I send letters to all of the residents, telling them about myself and my services. Occasionally, I get calls about it. But then about a week later, when I have my equipment, I ring the doorbells, introducing myself "Hi, I'm Jon, I sent you a letter a few days ago about mowing your lawn."
Basically, I think that should work for you, the same way it works for me.