When I first bought a table at home last year, I did what many did: spread and ran balls. I spent (and arguably wasted) a bit of time doing that for a couple months. However, even without any structured practice sessions, I improved a lot and raised my Fargo to 570 with over 1000 recorded games. I naively thought to myself, "at this rate, I'll be playing SVB speed soon." Then I hit my first plateau. No matter how much time I spent running balls, I didn't seem to improve anymore.
A few months later, I hosted Bustamante for a week, who taught me a few things. I started spending quarter of my session practice on breaking. In addition to learning troubled angles and drills, I incorporated 15-ball rotation and 14.1 in my practice routines. I raised my Fargo to 600.
Then I hosted Efren and Rolando, who told me not to practice too much. "Quality over quantity," they said.
Now I spend roughly 8 hours/week on the table at home and spend the rest of the time competing. I believe muscle memory will obtain any information, good or bad, so if I'm not playing well during practice, I stop and just walk away from the table.
It's counter-intuitive to think that I spend less time practicing and yet my game seems to improve, slowly but surely. I'm at 615 now and hopefully I'll break the 625 goal soon and 650 by end of 2019.