This trick of the trade is a very essential trait that any small business owner should have, and that I apply to my big-girl-job as well in dealing with clients.
A client sends you an email, extremely dissatisfied and making you feel sad. What do you do?!
In fact, your next steps are pretty important and indicative of your client-relations skills. When working in a small business, it's important to be creative in turning your bad experience into positive ones.
a) Set the tone - don't argue back, and apologize, but not profusely. People make mistakes, these things can happen.
b) Distance yourself, take a breath - it's easy to take these complaints personal. It can feel that a customer is directly insulting you when they insult your product or service. So take a minute and step away from the email or phone call: this will help you cool down, and come up with great ideas for the next part.
c) Ask what can be done to make it right: or, make a generous offer on how you can make it right. I guarantee that not only will your customer be delighted with your response, but will rave about you to all of their friends = positive PR!
d) Proof your response, and listen to it/read it as if you were a client. If you were in their position, is this what you would want to hear? Is there any way it could be misinterpreted? Do you feel good after reading it?
e) Check in again after they have responded and some time has passed. Customers appreciate a follow up, and they will feel like a priority if you follow-through.
Take this advice and go, young grasshopper.