I started playing about 15 years ago, took a few lessons, hacked around, never really had anything click with any consistency, and mostly gave up. Tried again 3 years ago with similar results.
Over the winter I spent bunch of time doing mirror drills without a club to work on actually turning my shoulders and hips correctly and fixing my biggest 3 flaws: Sliding my hips on the backswing and rolling to the outside of my right foot, moving my arms way out to the side for a super flat baseball swing, and not getting my weight forward. Honestly the hands were probably the biggest key, once I realized they should basically go up instead of around, the others clicked.
Recently I got a new-to-me set of irons to replace my 20 year old big berthas with regular flex graphite shafts. The new irons are used Mizuno MP-15 with DGS 300 stiff shafts, probably a little too much of a players iron but honestly they don't seem that bad and I got a great deal. With properly fitting shafts my swing is way less jerky and more powerful. I'm signed up for more lessons again. My trips to the range have had a different fee. I'm still not making consistent contact every time, but it's better than it was. I feel like I'm swinging a lot harder now but also a lot more smoothly, and now every time I do put a good swing on it I get right-to-left movement, instead of having no idea where it was going to go most of the time and a way happier trajectory, a lot more explosive off the face and more of a home run and less pop fly.
So hopefully I can get to the point of consistent starting trajectory soon, currently I'm getting draw spin but it could start anywhere +/- 10 degrees of straight. And then maybe I can start hitting my driver the same way, I still tend to slice it or pop it up. If I can truly improve this time around, I'll treat myself to a new driver next year. I'm also reading LSW, I basically have no idea how to actually play a round other than try to hit it as far as I can each time and hope for the best.