Did you post this multiple times? Anyway here's the answer I gave to the other post:
As the old saying goes start with the basics and work your way up. Although there may be a rare few who can cast with learning the basics (meditation, visualization, grounding, centering, chakras) most need to learn these techniques, skills, etc...before being able to utilize the energy within them and around them properly. If you already have succeeded in learning, as I don't think mastering as a apt term, the basics just keep trying and focus on a logical goal.