That is a very broad answer. Were your fundamentals all good to go from the start, or did you "correct/improve" some things like say how you approach the table, your stance, bridge, grip etc...? Did you get training on the mental side in terms of a thought process or mantra to go through on a pre shot routine? These are just examples to maybe help you elaborate on the question.
The only thing Gene taught me was how to aim correctly, and he taught me to slow down my backstroke... just being on the road and being in situations where I needed to make money has improved my game as well. Gene really does teach a way to cut your misses in absolute half regardless of the level you start at.
My fundamentals were decent before Gene met me. He did improve my breaking technique as well by changing how I approach my break.
He also taught me some valuable ways to cut cost and how to prepare for matches.
My mental game still needs alot of work. That part of my game alone would bring me to Shortstop speed. I already have everything else down. Just need to play a bit more safes. Play slightly better position, and get my mental game down to a science.
I ordered 3 books on the mental aspect of the game, 1 book on the basics of safety play, and 1 book on one pocket.