Don't forget to send out the gentle reminder to previous clients. Remember, out of sight is out of mind. keep the client base informed of any new skills and offers. Reaching out is a 2 way street.
In more than 20 years of doing this kind of work, I have never bothered any of my clients in between projects; I wouldn't want any of my clients just "reaching out" to bother me with any emails unrelated to a specific project, either. They know exactly where to find me anytime they need projects and I'm not going to be spamming them with any kind of announcements that I've added some new area or expertise or skill. Once they use me, I'm pretty confident that they won't be looking elsewhere for future projects, strictly based on the quality of work that I provide.