The most important quality in a tarot reader is that s/he reads from a place of personal integrity. If the reader has your best interests at heart then you will most likely benefit from the reading. A very 
clairvoyant psychic who is there for self interest or ego rather than exchange of energy and gifts will not further your path. Most of us can sense integrity in a reader.
I believe that there are many more wonderful readers out there than those we need to watch out for.
Some guidelines that may be helpful:
Watch for:
• Someone who makes you feel comfortable and at ease.
• Someone who allows you to ask questions.
• Someone by whom your feel ‘heard’ or understood.
• Someone who honours your choice in all situations.
• Someone who honours your own inner guidance and intuition and encourages you to cross-reference all spiritual advice with your own gut feelings on the matter.
• Someone who radiates a sense of health.
• Someone who is not afraid to be human or not know all of the answers all of the time.
Watch out for:
• Those who won’t allow you to ask questions, who are defensive or easily offended by your questions.
• Those who use fear to extort exorbitant fees, such as by telling you something is wrong with you (you have no soul; you are possessed by evil spirits, etc.)
• Those who put you in fear or diminish you.
• Those who are judgmental of your choices or actions.
• Someone who abuses drugs or alcohol, or is very unhealthy.
Knowledge/Tools/Gifts:
The Tarot cards themselves are the tool a reader is using in order to provide you with intuitive guidance. They connect the tarot reader with her intuition, stimulating the ‘third eye’, or chakra associated with psychic guidance. While it is important for a reader to have a knowledge of the tool s/he is working with, in truth the tool works differently for everyone.
Some use the cards as a way of ‘tapping in’ or accessing the ‘right brain’. The tarot cards help them reach a meditative or altered state of consciousness wherein they can more easily access their own intuitive gifts.
I have been to Calgary readers who are primarily clairvoyant, who lay out cards but rarely refer to them, and others whose focus is primarily on the messages and meanings inherent in the cards, drawing on the intuition to interpret and apply the meanings to the situation at hand. Many Calgary professionals who offer psychic readings will also use the tarot in their psychic readings.
Intuitive gifts that a reader may draw on are many and varied:
Clairvoyance is the gift or art of spiritual seeing. Some clairvoyants refer themselves ‘seers’. These people will see pictures in their mind’s eye, similar to watching a movie. Sometimes the pictures are of actual people and events, sometimes they are more symbolic in nature. Symbols are often accompanied by a feeling or a complete understanding of what the symbol is communicating. At times there may be an element of interpretation involved. Some clairvoyants will receive information from ‘spirit guides’; angels, or higher beings, who communicate to them through images or symbols.
Clairsentience is psychic feeling. Very emotionally evolved or sensitive people will ‘feel’ guidance in their emotional or physical bodies. This feeling- guidance may be a sensing of energy, of the clients emotion, or simply feeling the correctness of an answer.
Claircognizance is a psychic knowing, such as knowing something is going to happen before it does or having an understanding of something that does not come from personal experience or intellectual knowledge.
Clairaudience is psychic hearing. Often those who experience clairaudience will hear an internalized voice, as if you imagined someone was speaking, only the imagination is receiving rather than actively creating the voice or words, and the words themselves come from spirit, guides, the higher self, or intuition.
Mediumship is the ability to speak with specific spirit beings (often departed loved ones or ancestors) and give messages to the client directly from that spirit. Most often a medium does not use tarot cards. Though this is not to say that messages from the departed don’t come up in a tarot reading, simply that in a session with a medium such messages and communications are the primary focus, and don’t require a tool such as tarot cards.
A reader may have many psychic gifts at her/his disposal, and certainly as one reads professionally and over time, often there is an opening of channels or awakening of further gifts.
If you are interested in a certain type of reading, it is easy enough to ask the reader ahead of time to describe his/her techniques. If you have a pressing matter for which you are seeking guidance, for example, it is better to tell your reader than to walk away with a broad reading of your distant future that describes in detail your career or husband ten years down the road, but misses the personal crisis you are dealing with today.
Personal Style
Also important in choosing a reader is style, those aspects of a reader’s approach and demeanour that make him/her unique. Calgary hosts a wide variety of reader’s with varying styles. Some readers are known for being economical and blunt, they can answer your questions succinctly and are very straight forward. Others are known for a very nurturing, gentle approach with more emotional insights. Both are equally valuable, depending on your personal needs and tastes.
Some are known for a unique sense of humour, or have impressive backgrounds such as having written a book or studied with a renowned organization or individual. Some are practitioners of other arts which compliment their reading abilities.Then there are readers who believe that there is harshness in ‘reality’ and that a reading without the harsh truth is not well-rounded. They will look for negative to balance the positive in their glimpse of your situation.
I once heard psychic who was otherwise quite bright and cheerful say to a client of her loved ‘Has he broken his arm yet?’ While I trust generally that information won’t come up if we are not meant to hear it, I personally don’t want to know about a potential injury unless I am being told how I can avoid it. If I were to see that psychic again I would ask her to leave out the details of any potential injury unless it was preventable, and she was giving guidance on prevention. I know myself well enough to avoid information that will cause me needless worry.
Style is also expressed in the type of readings given, layouts used, the structure of the reading. I have been to readers in Calgary that incorporate numerology or astrology into their readings, and some that spend a great deal of time on detailing your past lives. This can be a lot of fun to hear (often past lives hold keys to healing the present), but may or may not be what you are looking for from your reading on a given day.
Bottom line is that the style that is right for you depends on you; your wants and needs at the time of the reading, who makes you feel comfortable and understood, whose personality draws you in.