Feather breathing is a very light and calming breath which allows to experience the sound of silence.
After exercising breathing with a sound-element such as Ocean-breathing, Humming-bee breathing and Whistle-breathing, feather breathing is a good follow-up because of the contrasting silence.
While my mouth is closed and teeth slightly apart, I inhale slowly through the nose, until my lungs are full.
I exhale slowly and gently, through a small hole formed with the lips, a bit like silent whistling with very slow-flow of air. I Imagine that I am trying to slowly and gently bend the flame of a burning candle. As the air is fully expelled, the lips are gently sealed before the next inhale. Deepest relaxation point, is when the air is fully expelled.