The client you already have, is probably one of the easier places to look for new business.
Organic growth relies on repeat business from satisfied customers. Clients will rarely buy a product a second time if the first experience isn't top notch.
Quality starts with the first contact a client has with the company all the way to the delivery of the final product. While you may not be on the phone with them every day, you are the person conducting the day-to-day activities, exposing your clients to your company’s services.
The work you do directly impacts whether you keep the client or they leave.
When your client is so impressed with your current work that she gives you a new project, you are responsible for bringing that in.
Earning trust from your client can also translate into earning your bosses trust. That trust allows your bosses to give you more responsibility freeing them to concentrate on new business.
So the next time you are trying to figure out how you can help build the practice, just remember your work is the launching point for the easiest get in the business.