Scrying is a divination technique utilizing a mirror, a bowl of oil, or water, a crystal ball, literally anything that has a reflection. Scrying in any of its forms is very closely tied to the moon. Although you can obviously scry at any time, most people find that visions are at their best and at their strongest when it's full moon.
Scrying is often considered one of the most difficult methods of divination for several reasons. Unlike more well known methods of divination such as Tarot or runes , scrying can often be much more symbolic and somewhat more difficult to interpret. Most often the answer to interpretation lies within you.
Many people expect to "see" visions when scrying. This is far from the case though. The information can be received through any one of your five senses and this is why so many beginners seem to get nowhere. They are too busy trying to "see" rather than opening up and being receptive through all available senses.
Most people have psychic abilities whether they have discovered them yet, or not. Scrying may well help you to awaken them
Scrying undoubtedly requires patience above all else. At the beginning visions will be very sporadic and vague. Don't despair! Practice, practice, practice! And it will become easier.