Tarot cards are used as a tool for psychics to link in with spirits and guides to offer guidance that may relate to past, present, and future.
Tarot cards can be laid out in various ways and any number of cards drawn. Some psychics may even use a combination of 2-3 tarot decks. As a result of which, the messages and guidance offered will be of meaning and of truth, and essentially, a message that needs to be given to the recipient.
All tarot cards come with meanings and some people may only use this way of giving readings. Some psychics, however, will throw away the books accompanying the tarot cards, and use only links with spirit to give messages. So, these psychics/mediums use only information that is received on a truly spiritual link and is not practiced in fictional fortune-telling methods. The duration of tarot psychic readings given will vary.
How ever long or short the readings may be the messages given will be honest and give meaning and validation to the recipient
Most authentic psychics will not elaborate or exaggerate any information to lengthen readings. When tools such as tarot are used, they are read using mediumistic and spiritual direction (intuition). This means that cards will be read on an individual basis for each person. For instance, a person may choose three cards from the deck. E.g. Three of Swords, The Tower, The Priestess.
The psychic/medium will give their messages and guidance to this person. A second person can shuffle this same deck of tarot cards, and pull out these same three cards. The messages given to this person will be different and have different validations.
There are many objects (tools) used by a medium or psychic to enable their connections to manifest in the same way as tarot. Some of these include crystals, crystal balls, color, rune stones, angel cards, palmistry, and psychometry, etc.
To define your best method is to sit in a development circle or participate in a few specified workshops to find your niche and develop such skills with a reputable teaching medium.