Marketing should not always be something intended for the acquisition of new clients as it could well be used to get more business from existing ones too and that tends to be the easiest of ways to proceed. A lot of people simply focus upon attracting new clients to their business and hence they disregard offering help and assistance to their existing clients which does not really give a very good impression to say the least.
If you offer a good value service to your existing clients and you market to them often, you will be able to get more regular business from them and it could very much be enough of a business for you. The best thing however, about marketing to your existing clients is that, you could be getting referrals through them as they may recommend your service to their colleagues which would in turn amount to a significant growth for you.
You could use promotional coasters and other printed material available through Printer leader fifty five printing to give out to your clients so that they could remember you for a long time. Keep in constant touch with them and communicate special deals to them. You would soon be able to find the impact that this is going to have upon your business.