Crystal balls and Occultism (= the study of hidden things, Secret Sciences) are two concepts that arewith each other formany centuries. As traditional requisite for Occultism crystal balls among other things have long been used for clairvoyance. While there is no scientific basis for the view of events the fascination of the mysterious crystal balls is unbroken.
So it should work best
Full moon is supposedly the best time for clairvoyance. Run lukewarm water on the crystal ball for 3 minutes (for cleansing) and then expose it to the full moon irradiation the whole night. According to the clairvoyant, it is possible to achieve the clearest and best result.