Hardly anybody knows Gene Marvin today. During the 1970s and 80s, he was a successful mentalist billed as "The 21st Century Man". He was all over the magic press, performing left and right, TV bits, and corporate work. Then he dropped off the radar. This is the book he released during the 1970s.
In the world of tricks and illusion, mentalism is the "aristocrat" in the area of legerdemain. It is the "King of Conjuring," ranking so highly above the average magic trick that there can be no comparison - and usually there is none.
People know that magicians pull rabbits from hats, saw girls in two and float them in the air. They also know that all this is done by clever trickery. Consequently, the average magician had better be one heck of a performer or he will have something in common with only one other act - the hypnotist. Both put people to sleep.
A mental magician has one very important edge when it comes to performing. People believe that he can do what he says he can. Mentalism is literally in the same stage of development magic was in 200 or 300 years ago, back when people believed that the magician possessed supernatural powers. People want to believe you have the ability to read minds, predict future events, or move solid objects with your strong mental powers. Don't spoil it by telling them differently.
Mental magic should never be as "strong" a trick as magic. In other words, what you do must be believable. You can stretch "their" imagination only so far, for they must be able to accept the fact that you "have the power." If you did a magic trick in which 5 different cards were laid on the table face down, a 6th card was sealed in an envelope which matches one of the 5 on the table, then a selection made by the spectator, and when that card was turned face-up, the card in the envelope removed, and that card matched, this would not be a very strong trick. But, let a mentalist do this, and he gets more "oohs" and "ahs" than the magician who disembodies a lovely lass 12 different ways. Why? Once again, people believe!
Mental magic is much easier to learn than sleight-of-hand. It requires very few props - in fact, even the props should look ordinary. No flashy dragons or red/black/gold paint designs. You are not using "tricks." You are using envelopes, papers, pencils, etc. Oh, and by the way, never refer to what you are about to do as a "trick." That's a no-no! It is an "experiment," a "demonstration" or a "test." Give the impression that you are never sure you will be successful. When your prediction or revelation is right, be as happy and surprised as they are. And it doesn't hurt you a bit to miss now and then. This makes it all the more believable.