When I was young learning to play I was lucky to have a fantastic instructor. He taught me solid fundamentals and on course instruction to become my own best coach. I was referred to him by the best players from my area. I suggest you ask the better players in your area who to work with.
For better players, I think it’s important to find an instructor with successful competitive playing experience. How could someone teach the skills to win tournaments if they haven’t done it? There is so much to the game other than hitting 7 irons and drivers. Winning requires short game versatility and solid mental skills.
As a full time instructor for the past 28 years I have continued to compete and work to improve not only for myself, but for the benefit of my students. I chose many years ago to be a member of the Metropolitan PGA because of the strong tournament competition and fantastic history of great golf professionals. Although not as often as I would like, I have had multiple wins.
I love Lee Trevino’s famous quote, “I don’t have a teacher because I haven’t found one that could beat me.”