Your overall goal is to improve your ability to do some larger task. Larger tasks tend to be able to be broken down into smaller tasks. Improving your ability on smaller task tends to make you better at the larger task.
So what you do is find a way to:
- somewhat isolate a smaller task
- then focus on doing that smaller task with ONE particular focus or improvement in mind
- have feedback on how it went
When feedback is present and you are paying attention, you will tend to fairly naturally improve.
Repetion is good, but repetition in different circumstances is much better for learning.