When working with allies from nature it is important to remember that they are beings with their own lives and paths. When we have experienced, as I have, the sentience and purpose of beings in nature, we must take care to not just "use" natural allies. While most are more than willing to engage with us in a healing way, we must not presume that this is their sole purpose. They have their own destinies and timetables. They are subject to the turning of the seasons and have variations in their cycles of activity. We need to approach them with respect and be willing to participate in a mutual exchange.
It is courteous to ask before taking anything in nature from its natural setting; it is all too easy to upset the balance of individuals and ecosystems. Try to work with an allies in their home habitat. If this is not possible, herbs can be obtained from wild crafted or organic sources and stones are available in crystal shops. Animals you work with might be ones already in your care, and those in the wild should be approached politely, maintaining a respectful distance.
A primary requirement of working with allies in healing is one of participation. Rather than anticipating that a particular ally is just going to "fix" you without your putting in any effort is akin to expecting a mechanic to magically appear at your house, bring all the right parts and fix the rattle in your car without you doing anything but writing a check. Merely carrying a stone in your pocket is not going to do much. Taking an herb because it is prescribed by your naturopath may have some remedial effects due to the chemical constituents, but it may fall short of healing unless you are willing to engage the entity on a deeper level. This is true of any kind of healing interaction.
A discourse on pharmaceuticals and their effects and side-effects is not relevant to this discussion but, treating them with the same respect we accord plants and other allies is appropriate to the scope of the ideas presented here. Any ally or substance engaged in your quest for healing must be approached with respect for its inherent dignity.
As to choosing which plant, animal, stone or element to engage in healing, it is important to work with allies with whom you have resonance. While a specific ally might be proffered by someone as a remedy for a particular situation, only you can truly know which allies are a good fit. What do I mean by resonance? It is the state of already having a thread of relationship with an element of nature. Is there a plant that you have always been drawn to? An animal with whom you have an intimate relationship, or who has been in your dreams? Are there stones that capture your imagination, aspects of weather that you enjoy more than others? These can all be clues as to where resonance lies. Sometimes it will be obvious to you, other times it will take more investigation, time and meditation.
If you are at a loss, spending time contemplating various aspects of nature in turn may guide you. Take time to consider the elements for example. Are you more drawn to water, air, fire or earth? Do you enjoy plants more than stones? Start with the bigger picture, then whittle it down to specifics. When you have done some investigation, spend some time with an individual from nature. Get to know these allies, what nourishes them, what traits they exhibit. Do they mirror some of your own tendencies?
A primary engagement with allies is one of emulation. When you find an ally to work with and have gained some sense of their particularity, the healing path may include reflecting some of the healing traits found in that being.
As an example, you may find that you share some traits with Dandelion. While Dandelion sends her soft airy seeds out on the wind, she remains rooted to her place with a deep tap root, fortifying her connection to the Earth. Her connection to place is enduring. She carries healing medicine properties in her leaves, her stems, her flowers and her roots. She is adaptable to her environment, enduring harsh conditions. Lack of or overabundance of water does not defeat her. She survives the chill of winter to emerge in the spring, ready to flower and spread her gentle joy to another seasonal round. Dandelion will even adapt her growth to the height of the mower blades that would seek to eradicate her. She endures.
These are some of the qualities of Dandelion that can instruct your work with her. You may find the ways in which she interacts with her world of benefit to emulate. Try living as Dandelion does for a day. Send your seeds, (medicine) out on the breeze with faith that they will find their destined place, that they will be received well and survive to establish themselves and grow. If you are feeling spacey or scattered, think of Dandelion's tap root. Send your own energy into the Earth and feel your emotions calm, feel the Earth's nourishment rise into you; sink your energetic roots deep into the Earth to stabilize your sense of place.
While detailing them is beyond the scope of this discussion, Dandelion also has many chemical medicinal properties. Researching those either through books, the internet or with a competent herbalist is an important part of familiarizing yourself with this plant ally.
Though the above practice is a significant part of creating alliance, healing with allies should not be just a "mystical" exercise. Establishing a relationship with allies in real world contact and time is important. Educating ourselves as to the names and physical properties of our helpers is a practice of respect and deepens our alliances. Knowing how to recognize allies in their natural setting is essential to understanding how they live. We need to see them as more than just a dried herb in a store jar, or a pretty tumbled stone in the crystal shop. The more we can open and deepen relationships, the richer they will be. As an example, this quote from Loren Cruden's book, Spirit of Place illustrates beautifully this concept:
"The wisdom of wholeness does not deny what has been learned. Observe the crone gathering herbs. She knows all their names and virtues. She knows when to gather, how to preserve, and how to bring out their medicine gifts. Yet it is not this knowledge that is her power. She could gather any plant at all, in any stage of its growth, and use it to heal. Actually, she could just call upon the medicine of the plant's spirit to be present, without any material form at all, and heal. In fact, she can heal just by seeing a person's wholeness with such strength and clarity that they see it too and are healed. Yet she gathers herbs. She honors life that way and teaches the young."
This perfectly and succinctly illustrates the point that cultivating a real relationship with allies is the wisest course for forming a healing relationship with them.