To master a skill requires you to practice. But practice alone will not make you a master of the skill.
One must become a master of practice. i.e. you need to know how to practice to get the most out of your practice/training time.
You must know exactly what the perfect skill is all about and all the components of it.
You then most practice in various ways to work all aspects of the skill as a whole and as individual parts.
You must master the various that are available to you to practice your skill so there is always some improvement being made all the time.
Striving to master a skill is really about striving to master to be a master of practice.
Master Jonathan Field