Learn it right the first time!! The mind takes in all the aspects of movement like a tape recorder. It doesn’t recognize efficient from inefficient; it just records, and the body begins establishing "motor memory." If bad habits are set into action for a period of time it becomes that much more difficult for the athlete to “un-do” the bad habits. Remember . . . practice makes permanent - not necessarily perfect.
Competent instruction is the best thing you can do for a young athlete who wants to be successful and competitive in any sport! I use constant video feedback to give players maximum awareness of their movement, and emphatically work on perfect execution of all the skills!