The most basic breathing practice is simple breath awareness. Come into a comfortable seated position – cross-legged, kneeling, or in a chair.
It's important to keep the spine straight, so that the lungs and torso have room to expand in all directions as you breathe. To lengthen the spine, consider sitting with a folded blanket just under the hips (cross-legged) or between the hips and heels (kneeling).
Close your eyes and bring your awareness to your breath. Begin by simply noticing each breath as it happens. As you inhale, notice that you are inhaling. As you exhale, notice that your are exhaling. Continue this noticing until you feel your awareness settling comfortably and reliably on the breath.
You can then refine your awareness, by noticing more subtle aspects of the breath. Consider shifting your awareness to the following aspects of the breath:
Continue to notice whatever you notice – go deeper with this awareness practice and notice the subtleties of your own breath.
With this practice, you are not trying to consciously control the breath. However, as you become more aware of the breath, you may find that the quality of your breath changes. Allow this to happen naturally, without strain or effort.