I worked at a University for about 5 years right before we moved to Texas. As a creative person, I never had a desire to go to college. I sucked at school. During my time as a staff member of the University, I learned about the benefits of higher education. Well, I still sucked at learning but I enjoyed the staff development opportunities. Among some of the classes I was able to take was Credit Card Security Levels 1-3 teaching how to help protect credit card data both for the business and the client. I use the knowledge to this day to help protect my small business and the clients we serve. For example, you will never be asked to give me your credit card information directly. We go through secure channels with fraud prevention protections.
One of my favorite classes was Dealing with Difficult People and Conflict Resolution. While I don't like labeling anyone as "difficult", the ultimate goal is to learn how to meet the needs of customers and clients. I also learned things to take into everyday life, not just business. The first question they asked was "is it you?" It gave me the chance to evaluate how I react to difficult situations. The answer is not well but it's good to learn this so you can adjust.
In conversations with other photographers, I often give advice on how to help them word responses to clients. Some of the things I suggest are simple.