Mirror scrying is closely related to scrying with a crystal ball. Both are forms of crystallomancy, a term which refers to scrying using any reflective surface.
Mirror scrying was probably the earliest form of crystallomancy to be practiced, with the “mirror” in question being the surface of a lake or other calm body of water. Such water scrying was a common feature of shamanistic cultures and often took place at night by the light of the moon.
Once technology evolved to allow the production of mirrors, these provided a more convenient alternative to water scrying. Many modern pagans still prefer the natural connection of a moonlit pool.
The actual techniques for mirror scrying are very similar to those for using a crystal ball.
Choosing a Scrying Mirror
As with all scrying, the choice of tool is intensely personal. One thing that is important is that the scrying mirror be used for that purpose and no other. When not in use it should be covered and out of sight.
Many people have said that old mirrors work better than new ones, possibly because of the psychic imprints of the years. However others prefer a brand new mirror that has no such previous imprinting and has been used for no other purpose. My personal feeling is that a beginner should consider buying a new, clean mirror then as their skill increases move to the more powerful older ones.
Many people find that round or oval mirrors work better than the square ones, possibly because there are no off-putting corners to break one’s concentration.
Black Scrying Mirrors
Perhaps the most effective form of mirror for scrying is a black mirror. Black scrying mirrors have been used for centuries (John Dee apparently used one) and are sometimes made of obsidian. Unfortunately black or obsidian mirrors are not easy to get hold of and can be expensive.