One of the master hypnotists and therapists of the 20th Century was Milton H. Erickson. His skilful use of language patterns to subtly influence his clients for the better is legendary.
In this type of hypnosis, negative language patterns are not used at all, for example, using this type of hypnosis for a client who wishes to give up smoking they will be encouraged in trance to breath clean, fresh air rather than to stop inhaling tobacco. The reason for this is that in order for anyone to mentally process a command, they have to think of it. Therefore, it is ineffective to tell children to stop doing something, as they will have to think of the very thing that you don't want them to do in order to make any sense of your command. It is much more effective to tell them what you want them to do rather than reinforcing what you don't want them to do.
Hynpotherapy sessions are very relaxing and clients are usually surprised at how pleasant the trance state is. Trance is about taking control of your own unconscious mind and is an extension of a naturally occurring state. The unconscious mind controls 90% of the body's systems, including breathing, heart beat, circulation and blood pressure. Tapping into it in trance makes changing habits effective and easy.
Sessions last for 1 hour.