Amateurs are content at some point to let their efforts become bottom-up operations. After about fifty hours of training — whether in skiing or driving — people get to that “good-enough” performance level, where they can go through the motions more or less effortlessly. They no longer feel the need for concentrated practice, but are content to coast on what they’ve learned. No matter how much more they practice in this bottom-up mode, their improvement will be negligible.
The experts, in contrast, keep paying attention top-down, intentionally counteracting the brain’s urge to automatize routines. They concentrate actively on those moves they have yet to perfect, on correcting what’s not working in their game, and on refining their mental models of how to play the game, or focusing on the particulars of feedback from a seasoned coach. Those at the top never stop learning: if at any point they start coasting and stop such smart practice, too much of their game becomes bottom-up and their skills plateau.
While this excerpt is centred on sports, it of course applies to many areas in which we might want to develop expertise.
I read another book some time ago, The Little Book of Talent by Daniel Coyle, in which there were some similar ideas. However, in The Little Book of Talent it was added that there are two types of skills: hard skills and soft skills. The former being skills that can easily be advanced through deliberate practice, such as hitting a perfect forehand in tennis, and the latter being skills which are more difficult to practice deliberately, such as developing a strategy to win a tennis match. I think this is a distinction worthy of consideration in the context of the above quote.