“What is the value per hour of what I’m doing at this moment?”
“Value” doesn’t necessarily mean money. The point is that, beyond financial planning, return on investment is an organizing principle.
When you are able to answer the above question accurately at any time during your workday, you understand time management deeply. You know which parts of your day generate most of the value — often ten, a hundred, even a thousand times the value of your least valuable moments.
I said “accurately,” not “precisely.” Precision doesn’t matter. Nor do the units on your yardstick: they can be dollars, fun, self-improvement — whatever is important.
Armed with this knowledge, changes automatically suggest themselves. If, at that point, you are still busy, it’s generally by choice.