...always, always keep in contact with your customers!
Sending a thank you note, a 3 month, 6 month, 9 month, 12 month, 18 month and 24 month reminders will keep your service in front of mind with your clients.
Sending a monthly newsletter will show your clients you care about them, they will show the newsletters to their friends and your referral business will jump.
Sending out emails via a service (like constant contact, aweber, etc) on a weekly basis will keep work coming and you can fill holes in schedules quicker.
Constantly reaching out to your client, keeps you ahead of your competition and makes you the "go-to" expert in your area.
Rob Anspach
http://www.robanspach.com
P.S. If you haven't checked out my Ultimate Monthly Client Newsletter yet, I invite you to go to my site and discover how you can try it out completely risk free for one issue. While on the site check out all the free stuff I'm giving away.