Simple stuff.
I am still working on things that seem so basic, so fundamental, that it seems ridiculous that I’m still working on them.
Things like how to hold the guitar. How to grip a pick. How to place a finger on a string. How to tune the guitar.
You can’t play without these skills. But we learn them without thinking about them. By the time we think to examine them and find out if we’re doing them right, we’ve been doing them for a long time and it’s hard to do them any other way.
I hear this from friends who play, too. When you’ve done something one way for a long time and then decide to change it, you have to unlearn the old way while you learn the new way.
As a high school student learning to play guitar, it never occurred to me that my shoulders and wrists would one day hurt because of how I held the instrument. Hurt enough that I have considered giving the instrument up. For that matter, it never occurred to me that I would one day I would be a larger person and therefore have a different mechanical relationship to the guitar.
Right now I’m spending 20 minutes a day out of my routine working on left hand movement: good finger posture, good wrist posture, minimal motion, minimal tension, fingertips landing in the right places, good tone… it’s a lot. After two months, it’s beginning to make a difference. It’s so basic. But such a basic change will improve every move I make on guitar, with both hands, independent of style or repertoire. That’s what I’m aiming for, anyway.