Scrying is a general term for the practice of obtaining divinatory or spiritual visions by looking at or into some visual medium.
Typically scrying uses a reflective or translucent surface such as a mirror, crystal ball, or pool of water, or gazes into the swirling of clouds, fire or smoke. Sometimes the scryer just sits in the dark and stares ahead.
By focussing gently but intently on the visual patterns that are suggested, a mild trance state can be induced in which recognizable shapes and images may be seen.
These visions are often interpreted as communications from the spirit world. However, most psychologists believe that the images stem from the unconscious mind of the scryer, or simply represent the active tendency of the brain to create meaningful perceptions, especially of faces and human figures, from random stimuli (a phenomenon known as pareidolia.
See also the Wikipedia article on Scrying.
This interactive Scrying Trainer generates constantly moving random patterns.
The images move from left to right. This is designed to activate the right hemisphere of the brain. The right hemisphere is believed to be better at processing visual patterns, and may play a role in creativity, artistic expression, and psychic experience.
To use the trainer, you should relax and allow yourself to passively watch the moving patterns. If you can, loosen your gaze so that your eyes focus just behind the screen (practice with Magic Eye pictures can help with this).
Just allow any shapes or images to appear in your imagination, together with any emotions they elicit. Don't force or resist it.
Those with special scrying abilities may also experience flashes of images, or emotions, that are not directly related to the patterns shown on the screen. These can be especially significant and can indicate entering a visionary or 'sensitive' state of consciousness.
Start with no more than five minutes, until you are comfortable and familiar with the process.
As you are watching the images form, you may want to quietly speak the impressions you receive (perhaps into a voice recorder). Some people also like to ask questions of the 'spirits' as they are scrying.
Caution and Disclaimer: Scrying Trainer does not use flashing images. However, if you experience any discomfort, nausea, anxiety, or other unwanted effects, then you should stop the session. User discretion is advised.