Emma Seppala writes:

We can change how we feel using our breath! Given the fact that it is so difficult to change one’s emotions using thoughts alone – try “talking yourself out of” intense anger or anxiety – , learning to use the breath becomes a very powerful tool. Since it is so difficult “talk” our way out of our feelings, we can learn to “breathe” our way through them. After participating in a 6-day workshop, veterans who said they had felt “dead” since returning from Iraq said they felt alive again. 2 years later, they are spokespeople for the program, volunteering to encourage other veterans to learn to breathe again.

Alternate nostril breathing explained:

This gentle pranayama is said to cool the mind and emotions. You may notice that, at any given time, one nostril is dominant (that is, air flows more smoothly through one nostril and only partially through the other). The dominant nostril alternates throughout the day. Preliminary research suggests that breathing through the right nostril oxygenates the left side of the brain, while breathing through the left nostril oxygenates the right side of the brain. One of the reasons alternate nostril breathing may induce its calming and balancing effects on the mind is that it gently allows for airflow through both nostrils.

To practice, place the index and middle finger of the right hand on the center of the eyebrow, and place the thumb on the right nostril, and the ring finger and pinky on the left nostril. The left hand rests on the lap, palm facing up. Take a deep breath in and, closing the right nostril with your thumb, breathe out through the left nostril. Then take a deep breath in through the left nostril, close the left nostril with your ring finger and pinky at the end of the inhale, and exhale through the right nostril. Take a deep breath in through the right nostril and, closing the right nostril with the thumb, exhale on the left side, and start over. Do this with your eyes closed for about five minutes. Notice the effects on your body and mind.

Alternatively, breathe out as long as you can, slowly.

Hold.

Then breathe in through your nostrils as long as you can, slowly.

Repeat a few times.