I don’t believe in a specific ‘method’ and consider coaches who do to be outdated. You only have to watch a professional tournament to see how many different swings can produce tremendous ball striking. All the greats of the game have had their own way of swinging the golf club whether it was Snead, Hogan, Palmer, Player, Nicklaus, Watson, Ballesteros, Faldo or Woods.
There are things they all have in common though: an effective impact position, a degree of rotation in their swing, great timing (sequencing in modern jargon), great balance and the ability to adapt to the differing conditions that every golf shot produces (such as: lie, distance, slope, wind, temperature, pressure). Great players and golf swings are able to compensate and adapt to whatever shot is required.
Players should look at the results and ball flights that their current golf swing produces and then decide what they want to be able to do with the golf ball. Once this has been decided then they can make the necessary adjustments to help them improve.
We all have wildly different physical capabilities and this alone dictates that we should all have different golf swings.