Anchor the collarbones and sternum firmly with the hands.
Send the chin forward and away from this anchor point, tilting the face upward toward the sky.
Make gentle arcs with the chin as you allow the breath to arrive and depart on its own.
Continue by sending the lips in the same direction as the chin. Use a gentle stretch boundary–one that encourages breath rather than restricts it.
Continue by sending the tongue in the same direction as the lips and the chin.
Slowly release the stretch. Use a hand at the back of the skull to help the head back up into a poised relationship with the spine.
Try to take your work with you into the next thing you do.