Take a moment.
Close your eyes.
...and take in a few deep breaths.
When breathing, focus on the following:
1. Your positioning and level of comfort. Make sure you're sitting or lying in a comfortable place.
2. Tactile awareness. Place one hand on your chest and one hand on your abdomen.
3. The placement of your inhalation, and your muscular response. Inhale through your nose for 5 seconds, and feel your abdomen expand.
4. Breath control. Hold your breath for 2 seconds before exhaling out very slowly for 5 seconds.
Repeat for 5-15 minutes.
It may seem simplistic, but, diaphragmatic breathing calms the nervous system and releases tension in the body; which in turn reduces stress hormones and releases endorphins.
If you feel any tension in your body or your stress levels begin to rise; take a few moments to regulate by practicing this exercise. Take note of how you felt beforehand, and how you feel afterward.