For a practitioner invested in his or her own development, a good beginning question to ask is whether the activities undertaken are leading to the desired improvement.
So if you want to improve your painting, does it help most to spend hours on brush technique? Or should you spend your time on something else?
I suspect that for some endeavours, people are putting effort into areas where they have no information if the activity is leading to the desired outcome.
This may particularly be the case for more complex tasks with difficult to measure outcomes that are highly subjective. Or where many factors can influence the outcome.
Essentially, this comes down to measurement and attribution. Can we measure performance? And, can we attribute (to the isolation of other factors) an activity to a change in performance?
Without turning our attention to these questions, we may as well be shooting in the dark.
On the flip side, obtaining clarity on these questions can lead to highly targeted specific improvement.
All of the above is easy to say, harder to do. I should apply this thinking to an endeavour I am trying to improve myself: writing clearly, concisely, precisely; something for a future post.