This article does a good job of describing an approach which is useful if you have lots of willpower, limited time, and want to learn to play a complicated piec

This article does a good job of describing an approach which is useful if you have lots of willpower, limited time, and want to learn to play a complicated piece exactly as written. I'm occasionally in that situation, in which case I use this approach, but at least for me this is a small portion of my practicing. Instead, I try to make sure I sit down at the piano at least once a day, and play whatever I want. The goal is to have fun, and let my fingers learn how to play by giving them a lot of time. If I have more willpower, I'll try harder things, occasionally stopping and slowly working through something that feels just a little bit too hard for me, but even when I just play I'm building familiarity and fluidity. (This isn't specific to piano: it works with any instrument)