Scrying – the technique of divining through crystal gazing; also, dowsing with a crystal-pointed pendulum; describes gazing on any reflective surface, such as water and mirrors – often with the moon’s reflection on water, or on a smooth, polished surface of an opaque stone like obsidian (lava-glass, volcanic-glass)
By calming the mind, relaxing the eyes (or in some cases, closing the eyes) and drifting into a trance-like state of altered consciousness, a clairvoyant will be an open channel to receive – though we should note two things, altered consciousness does not mean incoherent, and an open channel is not an unregulated or unprotected channel, or necessarily a clear channel. I make these distinctions because this is where natural ability and years of experience meet professionalism or social ethics. Everyone has the natural ability for any of the faculties described by the Psychic Sciences. Many people have had experiences with their own intuitive & psychic abilities – facets of consciousness we tend not to pay much attention to; but, not everyone has trained themselves or trained with a group of like-minds to learn to express their gifts accurately, specifically, safely, and conscientiously.
However, back to my point, the principles of clairvoyance – which we have covered – suggest that the essence of scrying is a method of practicing, developing, or inducing clairvoyance. Often called crystal-gazing and bringing to mind images of a Gypsy woman in front of a crystal ball, scrying is a method of un-focusing & relaxing the eyes, as previously described, to receive a vision but utilizing the energies of crystals or reflective surfaces which can effect an external vision – not solely in the Mind’s Eye of the Seer. A slightly hypnotic trance can allow another party to also see a vision, like a guided meditation, similar to that being described by the Scryer. Eventually on the path of Psychic-Intuitive development, you will strengthen the awareness of the connection between yourself and Universal-etheric/Divine/Spirit to the point of not needing a tool or a focal point for yourself but rather as practice or as a way of letting someone you may be "divining" for, or reading for, a way of relaxing & participating.
Scrying in recent centuries has mostly been with the use of reflective, polished crystals & crystal-glass, as seen in crystal balls & scrying mirrors. However, scrying is also done on reflective pools & bodies of calm water, as well as with a crystal-pointed pendulum in dowsing. The most important thing to note is, scrying is all about the gaze.
Peace & blessings as you envision & create your best life!