Fortune telling is a profession for many people, and while there are fortune tellers that use their intuition and genuinely believe the same to constitute psychic prowess, most commonly the claim of "psychic" is marketing to have you believe the psychic alone can use divination.
Many "fortune tellers" are scam artists and give the same routine to every customer - the tarot cards, or what have you, are simply decoration and the object is to convince you bad things will happen unless you pay the fortune teller a lot of money to light candles for you or cast a spell.
The actual principle behind most divination is that synchronicity runs rampant in the universe - coincidence is the rule and only our personal awareness of it an exception.
I understand it's reasonable to doubt the idea that coincidence is so regular as to deliver reliable divination, the answer is to try it for yourself and evaluate your own results.
There are free online digital divination systems to work with, most tarot cards you might want to purchase include instruction books, but perhaps the easiest to start with is bibliomancy.
Bibliomancy is using any book and opening it to a random page and paragraph - which will relate to your question.
Now this is a subjective 'magical' art, so it really is very important to suspend your disbelief, and have a genuine question you need an insight for.
So having the question in your mind, and allowing yourself to believe this will work - open the book of your choice (the Holy Bible is a popular choice) to a random page and place your finger on a passage on a page you just opened.
Read that passage.
It's is highly likely the passage will directly relate to the question you have, it may even give you an insight - possibly an answer.
Having played with divination for some time here are my insights.
Flipping a coin doesn't work, there's not enough depth to allow you to subjectively interpret much, and with binary limitations it's not very accurate.
Divination is not the future, it's more like the path of least resistance you're on at the moment of divining.
If you try again for a better result, like gambling - the results become silly, contradictory or simply stop making sense.
Divining for others is very spooky, their unfamiliarity with the system usually gives them unconscious strong belief - so whatever you say is highly likely to come true.
So it's REALLY important to either be positive, or let them know the future will change if they do something else.
Synchronicity powers all divination - when you toss coins randomly for an I-ching divination - the random hexagram that shows up - has relevance! The random spread of tarot cards - has relevance! Bibliomancy - wherein you simply open a book to a random page for a random paraph - this actually works! - If you approach it with seriousness, suspension of disbelief and intention to get a divination! Now the utility of divination isn't really so good as to deliver you winning lottery numbers (though it does seem true that the using the random 'quick pic' statistically delivers better results for lottery winnings than any other system).
But what it does do is give you something very much like a very good second perspective on your problem and often a look into a probable future.
Does divination have a place in business? Yes.
If divination suggests things are looking good - syncronicity is likely revealing facts you aren't aware of yet.
If you have a difficult choice to make, divination can give you a clear opinion.
It's not the future divination reveals - it's a likely possibility.
So remember that, never expect it to deliver the future to you literally.
Some free online divination options are available at http://kitschchaos.
com/tools.
html