I hate to say this ...
I hate to say this, because no-one can really be expected to believe it - but there really is a 'secret' to acquiring a better (more consistent) golf swing.
Ironically, the answer was staring me in the face, I've had all the evidence, but I've chosen to ignore it, or at least remain highly sceptical - until I gave it a decent trial.
It's something almost every serious golfer will have heard of and at least 95 percent of golfers, including me, will have ignored.
It's also something that can be observed in 95 percent of good golfers (pros especially). It's a mechanical thing, not a mental skill, because skills such as superior concentration and handling pressure are at another level.
This 'secret' is very simple: A STRAIGHT LEAD ARM (left arm for me).
When I say straight I mean observably straight or extended at the top of the backswing (wherever that might be for a player) and as straight as possible on the downswing and through impact.
Note of course that straight doesn't mean rigid or tight, but firmly straight and not bent to any perceptible degree. So many poor golfers noticeably bend their lead arm, quite often in the quest for a longer backswing.
Bending the lead arm in the backswing is fine if you have great timing, but so few medium to high handicappers have good timing; their timing is often compromised because of the hit hard impulse.
Maintaining a straight lead arm will, of course, for many older or less flexible golfers mean a shorter backswing. That's OK because the straighter lead arm will provide a decent swing arc and promote more consistent strikes. We just need to be realistic about our physical limitations.
There is another, somewhat unexpected for me, benefit of a straight lead arm: it seems to somehow unify and simplify one's swing. Focusing on the arm seems to eliminate the need to think about weight shift, or staying down or one of the host of other swing thoughts that can ruin a golf swing.
Combining this lead arm focus with more sensible driver strategies (gripping down when control is paramount), sensible club choice (let the club do the work) and more common sense short game strategies (a work in progress) has given me a tremendous boost of confidence in my game. It's not perfect, but ...
Anyway, I hate to say this, but give this straight lead arm 'secret' a try. I don't think you will regret it.