In addition to the courses for which I received some sort of diploma, I have spent months reading all that Milton Erickson wrote, as well as doing courses and learning from the works of some of the best-known hypnotists and NLP practitioners in the world. I also worked, met with and studied their methods, but all of this is not really the relevant part.
What is important, in my view, is that before I ever hypnotised anyone, I spent over a year solely performing self-hypnosis and only then did I begin to perform hypnosis on others. I have since hypnotised hundreds of people and have always achieved positive results. The testimonials page has a few examples of what clients have said about me. This way, you can gauge from the best source possible: Those who came to me for hypnosis sessions.