This a basic breath that's useful for slowing down and calming the nervous system. You can do this in a sitting or reclining position, while you are nursing, or quietly on your own.
Sit in a comfortable cross-legged position on a cushion, or recline with a cushion under your chest and head.
Let your downward gaze be softly unfocused (as if you could see inside and outside yourself at the same time) or close your eyes lightly.
Release your jaw and the muscles of your face (your teeth should be parted).
Let that same sense of release move down your body, neck, shoulders, chest, etc.
Inhale and exhale evenly through your nose, but try to draw the breath from down in your throat. Your throat and jaw should stay relaxed.
Continue to breathe in this way, with the sound audible only to you. The sound may be like whispered waves along the shore.
As you inhale, be aware of the belly and chest expanding evenly in all directions at once.
As you exhale, keep the chest open and lifted (don't collapse).
Allow your relaxation to slow your breath. Repeat ten times.