I recently had the privilege of leading a workshop at the Spiritual Formation Society of Arizona's conference "The Contemplative Way". It really is a "how-to" to listening (seeing) contemplatively with nature, God, ourselves and others.
Just a few things since it was in the context of a larger conference, the quote that is referenced at the beginning is actually Walt Whitman, not Thoreau and is this:
When I Heard the Learn’d Astronomer When I heard the learn’d astronomer, When the proofs, the figures, were ranged in columns before me, When I was shown the charts and diagrams, to add, divide, and measure them, When I sitting heard the astronomer where he lectured with much applause in the lecture-room, How soon unaccountable I became tired and sick, Till rising and gliding out I wander’d off by myself, In the mystical moist night-air, and from time to time, Look’d up in perfect silence at the stars. - Walt Whitman
A few other things I reference:
The Listening Life: Embracing Attentiveness in a World of Distraction by Adam S. McHugh
Spiritual Practices for the Brain: Caring for Mind, Body, and Soul by Anne Kertz Kernion