Don't pick only one

There is no one, even they with vast levels of professional training success, that owns a franchise of "how-to-improve-knowledge". There are many people conducting really good training that have unique angles to saying the same thing as every other trainer. Listen carefully to what  trainers have to say and take ownership, but don't fall in love with any one source because, what they are sharing, they likely learned most of it from someone else and also from their personal experience. In Brian Tracy's book: "Eat That Frog" Tracy states that 90% of the ideas and strategies in the book, he got from someone else.

There is a saying: "When the student is ready, the teacher will appear." There is virtually an unlimited amount of information readily available that will help you identify what you need to do to get better at whatever you decide to get better doing. When you learn from other sources, apply the knowledge. Consciously become the student that is ready for the teacher. Of course the teacher is not always a person. Many times the teacher is a book, a particular challenge you face, or when you fall down and you find yourself in the place where you "must do something." The action you take will either get you closer to a successful resolution or farther from it. Either way you learn.

Ask yourself what you are doing to get better. Are you listening to successful people including your friends and associates. Perhaps one of the most under utilized knowledge resources we have access to is the knowledge of the people around us.

Endeavor to learn from others and learn all you can so you can go out and put to work successful strategies you have learned. You do not have to make the same mistakes as others and you can accelerate your development by practicing what successful people preach! Use everyone and everything, not just one!