"One may ... look at being such as elves, and devic angels as communication bridges between man [sic] and nature intelligence." -- "What is Nature Intelligence," Co-Creative Science by Michaelle Small Wright
"[T]o resolve the evils and problems of this world we must all learn to communicate with the world of nature spirits and the angelic hierarchies from which they derive." The Secret Life of Nature by Peter Tompkins
The natural world is conscious, and we can interact with nature spirits, fairies, nature intelligence, and individual "natural" beings like trees. First, we must honor and respect them. Give them space to do their work. Then we must learn to listen. Slow down, open your heart, and open your senses. You may hear nature spirits, see them as light or even little beings, or feel them as presences and intelligences. Finally, we can use the wisdom we gain from working with nature to improve our own lives, from our spiritual path to the way we walk upon the planet.
A good place to begin to open to devas, fairies, and other intelligences is in your garden, or in a place of wilderness. Sit or lie down in a comfortable place. Open your heart, relax, and let your consciousness drift among the beings around you. Notice what happens. At first, you may not believe that what happens is "real," but over time you will learn to trust your abilities and style of listening.
For more on communicating with the natural world and developing your sixth sense, check out Voices of the Earth: The Path of Green Spirituality.