The cardinal rule in practice is “Do Not Practice Your Mistakes”. If you want to become better at doing something, you must practice correctly to improve. As the oft repeated quote goes, “Don’t practice until you get it right. Practice until you can’t get it wrong.”
In other words avoid mindless repetition. Instead of playing through a piece over and over again for the purpose of gaining familiarity, practice should be geared towards mastering the technical and musical aspects of the composition.
When we practice, we are trying to train muscle memory for a natural and automatic response. That’s why slow, careful and mindful practice with attention to fingering and hand motion (among many other elements) is important to instill the right habits.
Like an athlete, pianists should also have proper warm-up exercises and practice exercises such as études, scales and arpeggios. To attain technical security in difficult passages, one could design specific short exercises and drills to practice.
The secret to being a better pianist (and being better at anything) is deliberate practice. Here’s to productive practicing!
Read more about deliberate practice:
Learn Faster by Playing Slower: Muscle Memory Techniques that Work
Eight principles of deliberate practice
7 Lessons From Talent Is Overrated