Practice activities are worthless without useful feedback about the results.
Here is a wonderful excerpt from Talent Is Overrated: What Really Separates World-Class Performers from Everybody Else:
The best performers observe themselves closely. They are in effect able to step outside themselves, monitor what is happening in their own minds, and ask how it’s going. Researchers call this metacognition – knowledge about your own knowledge, thinking about your own thinking. Top performers do this much more systematically than others do; it’s an established part of their routine.
Metacognition is important because situations change as they play out. Apart from its role in finding opportunities for practice, it plays a valuable part in helping top performers adapt to changing conditions…[A]n excellent businessperson can pause mentally and observe his or her own mental processes as if from the outside:…Am I being hijacked by my emotions? Do I need a different strategy here? What should it be?
…Excellent performers judge themselves differently from the way other people do. They’re more specific, just as they are when they set goals and strategies. Average performers are content to tell themselves that they did great or poorly or okay. The best performers judge themselves against a standard that’s relevant for what they’re trying to achieve. Sometimes they compare their performance with their own personal best; sometimes they compare with the performance of competitors they’re facing or expect to face; sometimes they compare with the best known performance by anyone in the field…
…If you were pushing yourself appropriately and have evaluated yourself rigorously, then you will have identified errors that you made. A critical part of self-evaluation is deciding what caused those errors. Average performers believe their errors were caused by factors outside their control: My opponent got lucky; the task was too hard; I just don’t have the natural ability for this. Top performers, by contrast, believe they are responsible for their errors. Note that this is not just a difference of personality or attitude. Recall that the best performers have set highly specific, technique-based goals and strategies for themselves; they have thought through exactly how they intend to achieve what they want. So when something doesn’t work, they can relate the failure to specific elements of their performance that may have misfired…
…Since excellent performers go through a sharply different process from the beginning, they can make good guesses about how to adapt. That is, their ideas for how to perform better next time are likely to work…They approach the job with more specific goals and strategies, since their previous experience was essentially a test of specific goals and strategies; and they’re more likely to believe in their own efficacy because their detailed analysis is more effective than the vague, unfocused analysis of average performers. Thus their own effectiveness can help give them the crucial motivation to press on, powering a self-reinforcing cycle.
Still curious? Read the book and understand the difference between practice and deliberate practice.