Stress management is partly a collection of techniques for managing the pressures of life and partly a discipline for self-reflection and inner strength so that pressure does not become stress.
Basically, whatever works for you can fit under stress management. There is nothing set in stone, whether you rely on tips from others or develop something on your own from experience to help you.
Most stress is a result of inner confusion and inner conflict. If you pay attention to inner clarity stress management becomes much easier. There are a few key phrases such as "I don't want to", "I don't have to" or "This is not important enough" which when you tell yourself at the right time can work wonders.
Balancing the pressures is much easier if there is no inner confusion. Proper prioritization, self-discipline, looking from different perspectives, time management, goal setting etc. all play an important role in stress management.