Word of mouth is your best friend.
Almost everyone can think back to one critical thing that kick started their business.
Mine was a Church.
I redesigned everything for this Church.
a small file server,
an e-mail server,
4 office PC's
a projector presentation room(with a recent installation of a HTPC).
The word of mouth this church gave me was unbelievable. I landed several other non profit organizations and the friends and families of all the congregation, along with their friends and families and so on....
this was 6 years ago, now I am over whelmed at times with PC work. I am supporting myself and schooling along with my wifes income which is about 50% of our total income. I have never advertised etc.
Not sure if this helps. I will tell you that I had to volunteer for a lot of free work where I did not get paid. This however got my name out there. I also have been truly honest with my clients from day one. I never tell them I will fix their PC. I will tell them I will do everything I can so find a solution to their problems