Over at 43 Folders, they share some great tips from the late Leslie Harpold on keeping in in touch.  There are some great client-focused tips in there.  Here's my favorite:

2. Send Thank You notes.  When you receive something from someone else, it’s important to let them know you appreciate the time and effort it took them to think about you, and reward the courtesy with a little token of thanks. A written note is a much nicer compliment than an e-mail, and it doesn’t take more than a couple of minutes to write one and mail it away.This step also does double-duty by making you keep track of people’s contact information so you don’t have to continually ask them for it. We tend, in this electronic age, not to remember street addresses and phone numbers, relying on our mobiles to remember who called and what number to call them back. Keeping an address book may seem old fashioned, but doing so allows you to easily send out baby gifts, birthday gifts, anniversary gifts and any other kind of token of friendship and appreciation that allows us to continue to like each other in a monetary fashion.Leslie even thoughtfully provided a step-by-step method of composing and sending thanks at one of her stomping grounds. Take a trip over to The Morning News and refresh your manners.