I have worked on remaining calm in high stress moments. In certain situations it drives my wife nuts that she is stressed/excited and I'm calm looking for a solution. What I learned is to reflect back some of her excitement from a stressful situation, but not quite to her level. This then calms her down.
Is it easy? No. Do I manage to do this 100%? I wish. Is is manipulation? I don't think so. It's building a relationship to better communicate. Too often people think about communication as what I say and not what do people hear and also say.