(Based on the essay “Every Breath We Take” posted May 24, 2011.)
For the next 24 hours, notice if you are breathing through your mouth, and if so, try switching to nasal breathing.
Every hour or so, inhale deeply through your nose, and then release a long, slow exhale. Repeat two more times, trying to extend your exhale as long as possible.
Expand on this:
Try this Chinese Qigong breath practice of making an in-and-out breath last one minute:
Inhale slowly for 20 seconds. Pause and retain the breath for 20 seconds. Release the breath in a long, slow exhale lasting 20 seconds. (Do not strain.)