I keep in touch several different ways with past and present clients, as well as propective customers whose name was passed along to me.
I have a bi-monthly newsletter I email out toward the end of each second month in rotation. I discuss not only going on within TRImages,Ink, but also in the local communities that my clients live and work, and in the business world in general. I may also send out an additional "Quick Update" to industry specific groups (realtors, administrative, foodies, etc.) with timely topics, technology tips, or software/hardware deals and updates.
Then, on birthdays, anniversaries, special milestones or goal accomplishments I send out e-Cards as well as personal greeting cards with special, custom messages to each individual with a hand-written effect. When you factor in friends and family as well as business partners, the thought of sending out handwritten cards to each became overwhelming. But, I've recently discovered a secret weapon in that department called
SendOutCards through another VA, and the process became much more streamlined; even faster and less expensive then the traditional ways of sending them so I've been using them pretty consistently now for a couple of months. Incidentally, it was a great platform for some of my customers to implement in their follow us systems... especially those in sales or training positions, but is actually easily applicable to ANY business or personal use. I was so impressed I bought a system. And if anyone is interested in learning more you can certainly email me and I can let you walk through my system for free.
Finally, I have a Holiday list that I send out emails and cards to every year. The lists vary depending on whether or not the recipient is an active or past client, prospect, or friend or family member. I don't want to forget friends and family because they love to talk about what I do and are a great resource for soft selling my business. I send one out for Thanksgiving, Christmas and the Fourth of July. I will occassionally send out Back to School announcements to those I know have children. And, I occassionally send out "Tax Time" reminders. The last touch-mail piece I send is usually in the Spring and Fall for the Time Change in our area; reminding them to not only reset their clocks, but to also check their smoke detectors, and possibly get ready to either winterize or spring clean major utilities, appliances and grounds around them.
As far as a "personal" communication, I like to try to get everyone together for a backyard BBQ and Business Exchange once a year for those who either live in the area or will be visiting the area. That's tougher to do when some clients are a couple states away, but then I'm at least talking to them on a pretty regualar basis anyway.
Long post... but hope it helps give you some ideas.