Become the person you would want nearby when the plan fails.

Everyone hopes for a certain kind of person to be there when things go wrong. Steady, capable, not spinning out, able to do the next necessary thing while others are still absorbing the shock. That person is not born calm. They are calm because they have skills that hold when the plan does not, and because they decided in advance what kind of presence they wanted to be.

Picture the last time something fell apart around you, and ask honestly what you contributed to the room. If the answer is mostly worry, choose one practical capability that would have helped, and go get it. Being the useful person in a crisis is mostly a set of quiet preparations made long before the crisis.