You should read and study all you can (I recommend Keith Codes' Twist of the wrist II).
The books I recommend:
Twist I and II by Keith Code
Proficient Motorcycling by David L Hough
Pace 2.0 by Nick Ienatsch
Sport Riding Techniques by Nick Ienatsch
These are all on my Google Play Books, and I re-read them every now-and-then.
trying to ride someone else's ride, or trying to work on 4 different things at once, then get frustrated by lack of improvement
As the old saying goes "jack of all trades, master of none". I would recommend the exact same thing, by working on ONE thing at a time. For example, go to a parking lot and spend a few hours practicing emergency braking ONLY. Then another day, practice slow turning / figure 8's etc.
You always need to practice and refine your skills. There is always improvement to be had.