Working on my picking hand. I've always felt my picking hand was pretty accurate, but I know I have some bad habits that should be addressed. I started to become more focused on how I hold a pick, the type of pick I use, and adjusting things to improve my attack, technique, and overall accuracy.
In some ways, it's a little like starting over after 30+ years of playing. I can't play every riff, solo, or full song as well as I do when I fall back on "bad habits", but I know the persistence will pay off. The YouTuber and pro-musician, Bernth, was a bit of an inspiration for me to assess my picking hand technique and start the process of improvement.