I felt the same earlier this year. I have the occasional 78/79, rare 77, but I'm having trouble consistently breaking 80. I've also improved my chipping and sand play. Consistent ball striking is what I need. Like you, when I'm on time in my swing I hit it long and straight. My typical iron miss is a slight pull left. When I'm off my driver is all over the yard. And it changes from round to round. So I realize my swing isn't consistent. I feel like my hands come through too strong (right hand rolls strong) through impact and it closes the face a little. Instead of aiming right and letting it fly, I want to fix the problem so I can be consistent. I also feel like my hips extend too early on the down swing so the arms have to catch up, essentially doing all the work. And the club at the top of the back swing tended to be above and off plane causing the dreaded over the top down swing. Don't do this all them time but it kept creeping into my game. Frustrating for sure. I've always had a strong swing (aggressive) but as I near 55 I'm looking to change my swing to use my hips more.
I've watched a couple of pretty good instructors on youtube (Clay Ballard is one), but I found
Russell Heritage to be the best I've seen so far for breaking down the basics of the swing in a detailed way. Once I started watching his vids I found that I couldn't stop and he has tons of instructional vids.
A good example of
his method of teaching. This resonated with me and my swing.
To start from scratch this is a good
5 part series that breaks down all parts of the swing. Easy to understand and replicate. The other parts should be to the right in the series.
This is a new video showing a simple exercise to train your mind/body to
be in good position to strike your irons at impact. I found it very helpful and something you can do at home or the range before taking full swings.
May not help good golfers who already have good mechanics but for beginners and those of us (mid handicappers) that are looking to change our inconsistent swing, I recommend Russell.