Clairvoyance is a psychic reader who relies on extra sensory perception to get their readings. They see what is beyond the eyes; they feel not by touching, they perceive not by hearing, they taste not by eating or by touching. They make use of extra sensory perception which only they alone can explain how they perceive. One has to have potential by nature and then undergo the training to develop the extra sensory organ or the sixth eye as may be termed in some circles.
Clairsentience is also a psychic talent and skill which is developed or employed by psychic readers in the act of psychic readings. They develop and employ extra sensory perception of the past, and the present and the future. The technique they rely on is sensing. They sense the past and the present and predict the future. They can be said to be adopting extra sensory organ of seeing beyond the human realm.
Clairaudience as the name already suggests, makes use of extra sensory sound methods which only they can hear to make their psychic readings. Maybe the spirit world will send a strange sound which only they can hear and interpret. The sound may not be heard by any other person who did not possess their skill or undergo their training.
Perhaps another skill which is common is the act of divination. Divination is the act of obtaining psychic readings through consultation of the occult world. The divination methods always have an instrument which the diviner manipulates and interprets the message it sends across. The tarot uses the method of divination to arrive at their psychic readings. The 78 cards the tarots use is the medium they use to consult the occult world. It is clear now that there are psychic skills and abilities which the psychic readers use. It is left for clients to know which service they need and be guided in choosing the type of reading they want.