I am often asked if there is an ultimate secret to magick. Most of the time, this is asked from a position of obtaining power, and frequently, this is based on the desire for power over others. People who stay with magick learn the truth: the real power is power over yourself. Curiously, the more you try to obtain power over others, the less likely you are to obtain it. The more you obtain power over yourself, what some call "self-mastery," the more people are willing to give their power to you.
Magick is a way to understand yourself and the universe. The more you understand about yourself and the universe, the more you gain power over yourself. Therefore, the more you learn about yourself and the universe, the more powerful you will become.
Well, that's only partly true. If it were completely true, people who spend their lives as students would be the rulers of the world, and we know that isn't the case. That's because much of what they learn isn't useful. So I would say that the ultimate key to magick is to always seek more practical education. This does not mean that studying literature and philosophy is worthless for the magickian. In fact, just the opposite is true. But the key is to take the concepts and ideas that are presented and make them practical.
One of my personal mottos is, "You don't die when you stop breathing, you die when you stop learning." Taking what you learn and making it practical is the ultimate key to enhancing and making your magick more effective.
As I write this I am preparing to take my training in Neuro-Linguistic Programming (NLP). It's a way of using language and understanding how the mind works to make changes in your life and the lives of others. Since this is a form of practical education, you can see that I "walk my talk."
But you don't need to take classes to further your practical education as part of your magickal development. There are many fine books that can further your education. However, it is only when you put into practice what you learn in those books that your education becomes practical.
Part of NLP is based on the use of hypnosis. A great, practical book, filled with exercises and scripts you can use is New Age Hypnosis by Bruce Goldberg. It includes useable techniques to view past lives, contact your guardian angel and other spirits, heighten your psychic awareness, and more. All of these skills can be used by magickians.
Another one of my mottos is: "It's hard to be spiritual when you're wondering where your next meal is going to come from." A practical way to resolve this and other financial challenges can be discovered in How to Get Everything You Ever Wanted by Dr. Adrian Calabrese. It features practical ways to discover your hidden talents and creative abilities and use them to improve your ability to manifest your desires. These are practical techniques of using the mind to achieve your goals, a powerful type of magick.
Finally, once you've developed some of the basic techniques in those books, I suggest Self-Initiation into the Golden Dawn Tradition by the Ciceros. One of the difficulties with books such as Regardie's The Golden Dawn is that they are basically just copious notes for students. While they do reveal the basics and are incredibly valuable, you really need a full explanation of all the information. The Ciceros' book does exactly that, completely explaining the Golden Dawn's secrets for use by individuals or groups. It makes the magick of the Golden Dawn practical. Together, these four books make a tremendous foundation for learning and practicing magick that works.