Join at least one online networking site, which can be a strictly business site like LinkedIn or Ecademy, or more social site (but often equally effective) such as Facebook and Twitter. Don’t forget as a ‘virtual’ worker you can work with anyone, anywhere.
Send your existing clients a questionnaire. Ask them what they like about your service and what they would like to see added. If they are happy clients, ask them for referrals to other potential clients.