There are many layers to us that make up our ability to encounter all manner of experiences in life. One structure is called the triangle of relaxation made up of the mind, energy and breath. What happens in one aspect affects the other two and same for the others. We cannot control our mind nor our energy but we can control and affect our breath. Therefore, this is one way we can bring some measure of command over our personal experience.
For example, if you are angry, the breath becomes fast. If you are frightened, the body contracts and the rhythm of the breathing changes. Not only that, but your energy rises or falls depending on the emotion and the breath and you feel high or low. Similarly, when you become aware of your breathing when you are angry, etc. your breathing automatically becomes normal and you calm down and the energies are also fine. You feel more alright or energetic.
Below is a very powerful meditation using the breath and the fingers which also affect the brain action. Engaging in this practice daily, begins to bring calm, restfulness and clarity. It also empowers your ability to bring about change in your life thru the power of intention.