If you are asking how to find customers, then the best advice I can give is to Schmoooze.
If you're going after small-business contracts, make lots of friends in business. Be decent, be bright. Impress people by expressing interest in their lives and their livelihoods. Learn to empathize with business owners and learn about their businesses! Be a friend to all...
Then, when you do fine work for one customer, they'll talk about you to their friends, and you'll get calls.
I find the social part to be the hard part. The work is an afterthought.