I got a few lessons in 2020 and he helped me understand the importance of hip rotation and weight transfer direction in the swing, so I worked on a lot of drills around those two things. I listed the three that helped me the most below. I also started doing a lot of stretching/yoga to help with flexibility and weight training. I think what's been toughest for me (and still is) is that it's really hard for me to get into a great impact position even outside the swing due to past lead knee and hip injuries, so my practice has mostly been around trying to resolving that issue.
Drills:
1. Place alignment sticks in front belt loop and stick one into the ground on my left side, then try to hit the alignment sticks before impact.
2. Place wedge under my lead heel, swing transferring my weight towards that foot such that the wedge shaft doesn't move until after impact
3. Turn my head towards the target in the downswing