what is prāṇāyāma?

prāṇāyāma (regulation and mastery of the breath) is defined in the Yoga Sūtra of Patañjali, as interrupting the natural movement or flow of the breath by becoming deeply aware of it.

Each day set aside some time to breathe with awareness.

Sit comfortably with your spine tall, this may take a little effort to begin with.

Gradually align your attention with your breath. No rush. Begin to follow each exhalation and each inhalation with your attention.  Notice the quality of the breath.  Is it long and smooth?  Perhaps it's shallow, difficult or irregular. Keep watching your breath.  In time become aware of the natural spaces between the exhalations and inhalations.  

As you cultivate a flow of resonance with your breath, without force, begin to increase the length of your exhalations, let them last a little longer than your inhalations. Continue this practice for a little while.  When you're ready, notice how you feel.

You may wish to move or stretch.  Do this again tomorrow.