There are unlimited ways that you can stay in contact with past customers. Everyone knows that connecting with past customers and remaining visible is a very important aspect of your business. I think you should use a combination of snail mail, email, phone calls and in-person visits to constantly connect with them. Doing an annual painting warranty inspection is something I think is helpful. It shows you care about your work but it also keeps you connected with the customer for a long time.
Also when it comes to communicating with past customers, think about treating them like a friend, neighbor, or family member. What do I mean by this? You don’t have to constantly be talking to them about painting, painting industry, the nuts and bolts of doing a painting job. Most of your customers won’t care. Talking about human interests like music, sports, family, travel, and other things that interest you will receive a better response. Let them get to know you on a personal level and they are going to have a better connection with you. They will be more likely to hire you because they trust you.