In their book, Play to Win!, Revised Edition: Choosing Growth Over Fear in Work and Life, Larry and Hersch Wilson offer a simple formula for changing how we respond to events around us: Stop-Challenge-Choose. Here's how to use it to reduce your stress and improve your results.
When an event occurs that threatens to send you into fits of depression, anger, or other non-productive behavior, stop. Breathe. Take notice of what is going on; of the facts of the situation. Eliminate all your subjective responses in order to get crystal clear on reality.
For example, a customer walks into your shop and complains bitterly about your service, threatening to tell the world how badly he was treated by you and your employees. Before reacting with anger, fear, withdrawal, or any other non-productive emotion, stop and get clear on the facts of the situation. The customer is complaining. That's all you know at this point.
Challenge your assumptions about what is going on. One of my clients talks about how easy it is to "catastrophize" in a situation like this. For example, you might think, "The customer is complaining and is really mad. He will make good on his threat and tell a ton of people how unhappy he is. I'll bet he writes one of those really popular blogs. He's bald - maybe he's Seth Godin himself! Oh no, millions of people will hear what Seth has to say and they'll believe him. My customer stream will dry up; I'll go broke and live under the freeway."
You get the idea. We automatically make up catastrophic future scenarios that have no basis in the reality that is in front of us. The trick in this step is to ferret out those untrue stories we are telling ourselves in order to banish them from our thinking.
Stop that train in its tracks! Think about other interpretations you might put on events. You might think this way: "This customer is unhappy with our service. I know we can find a way to make things right for him, and turn him from a raving enemy into one of our strongest advocates. I just need to figure out how. I could do that by listening really carefully to what he has to say and what is unsaid, and searching for what he really wants - and then finding a way to give it to him."
Or you might come up with several other interpretations.
Of the alternate interpretations you developed in the Challenge step, consciously choose the interpretation that will lead you to take the most constructive next steps.
You might consider journaling all of this, along with the results of your little experiments with Stop-Challenge-Choose. That will help you cement the lessons and make them a part of the future, improved you.