You can get books on it, audio tapes, and videos. Take a course in it. Really. I very much recommend a course in auto hypnosis. I used to teach it myself.
An autohypnosis course is normally not very expensive and usually fun. Be sure you check the hypnotist's credentials. There are lots of "stage hypnotists" out there who are not even remotely related to what you need. Look up hypnotherapy in the yellow pages. You can use autohypnosis for lots and lots of things, you'd be amazed. I once cut off the end of my thumb with a table saw and used autohypnosis to stop the flow of blood. Freddy got her hand caught between a dock line and a cleat just as a 60 foot long research vessel came up hard against it. Her hand was flattened, the rope leaving a deep groove in the muscle. I used hypnosis to prevent pain and bruising and speed recovery. By the next day her hand was back to normal.
But the real reason to learn autohypnosis or self hypnosis is to be able to program instructions into your subconscious. This can be exceedingly valuable.
If you can read this, you can do autohypnosis. People who can't be hypnotized by themselves or others are either:
1. People who can't concentrate for 10 seconds on anything or
2. People who can't understand the language.
In brief, autohypnosis repeatedly gives a message to the communication web. A suggestion. The most important thing is that the message be worded nicely and positively. There should be no negative words at all anywhere in the phrase. Such as no, not, worry, anger, fear, hate, ugly, stop, avoid, and related words. Positive. Every single word. One of the most common beneficial phrases is:
Every day, in every way, I am healthier and happier.
A good phrase for any physical exercise is the Easily Nicely one. This exercise is also an example of autohypnosis in action. You simply repeat it while walking, thinking about the meaning of the words as you move. Over and over. Your whole communication web gets involved, from the metabolic level to the coordination of muscles to navigation.
If you want a book with a whole ready made list of excellent positive health-oriented suggestions, I recommend Louise Hay's "You Can Heal Your Life."
Almost all athletes use autohypnosis (even if they don't call it that) by repeating positive phrases to themselves.
"Every day, I am better and faster (or stronger or smarter or whatever)."
Students use autohypnosis to improve memory, reading skills, speaking abilities, whatever. Anything at all.
"Every day my lessons are more and more interesting. I read them more quickly, easily and perfectly and can remember them better."
If you want to use autohypnosis to lose weight, stop smoking, or improve a speech defect, take a course in autohypnosis, don't simply get a hypnotist to give you a suggestion. There is a major difference in results. Also the cost is about the same, and you get to use autohypnosis for anything else for the rest of your life.
If a hypnotist gives you a suggestion with negative words in it, like "I hate smoking, and am going to stop." Go find another hypnotist right away. You need good things programmed into your communication web. Positive thoughts only, if you want what's good for you.