I came across this article on the fundamentals of being a Master. The article has some valid points although I disagree with several of the points such as having to attend a BDSM event.
You should not have to attend some gathering; but I do agree that you will get a good deal of value out of finding people you can learn from and talk with.
Reading, learning to use your tools/toys, and knowing what it means to be a master are all important. Finding the right mix of these fundamentals will be a personal choice.
Another good tool to learn how to be a master is learning a martial art. Instructors there will act like a D/s master in many ways.
Talking with your sub and becoming the master that is appropriate for both of you is the best way to set your own set of fundamentals.