Consciously one understands the self improvement goals, but the subconscious is stuck in past failure mechanisms. Hypnosis and self hypnosis are the most effective tools to get the message from the conscious to the subconscious where change can occur. Napoleon Hill said that one can accomplish anything desired by repetition of suggestion for six months.
To accelerate this process, the late Harry Arons, a well known lay hypnotist from the 50's through the early 80's, developed a technique to deliver self suggestion in a particular time period. He does this by having the client count fifty breadths with eyes closed which takes from three-to-five minutes. The client does this for a week after which time the time period is becomes programmed. Next a self hypnotic suggestion is then used in place of the counting of breadths. A suggestion he might have had his client use is, "I am becoming more confident everyday."
Even though many others used self hypnosis with their clients, Harry was the one that developed it as a technique with a,b,c directions which eliminate the, "I wonder if I'm doing it right?" question.
In reality, all hypnosis is self hypnosis. Even with a hypnotist providing the suggestions; they are always aware of their surroundings even while in the deepest of trance. They can even open their eyes any time they desire.
Accompanying most hypnotic procedures is relaxation. As the subjects relax they often feel sensations of heaviness or lightness which is so pleasant that generally they don't want the relaxation to end. During this relaxation, suggestions are given such as, "Each and every time you practice self hypnosis you will be more responsive to the suggestion." This is called conditioning.
Autogenic training is another method used for self suggestion. It's generally used by those in the biofeedback field to facilitate muscular and vascular relaxation. Autogenic phrases are suggestions such as:
Six months? Both autogenics and self hypnosis dramatically improve upon simply using self suggestion in that the suggestions are given while in a relaxed receptive state (alpha) as opposed to repeating them to oneself while in a beta state. The beta state is one's normal aware state where the conscious mind is busy concentrating on reading, driving, communicating...
Typical suggestions used are in first person present tense such as:
Hypnosis, self hypnosis and autogenic training are the best ways to get the message to the subconscious mind and effect a change in behavior. From here on it's a matter of refinement of suggestion and suggestion technique of which there are many to achieve any specific goal.