Management is nothing more than motivating other people. — Lee Iacocca. American businessman (1924–2019) Leadership
If you want to make good use of your time, you’ve got to know what’s most important and then give it all you’ve got.
If I had to sum up in one word what makes a good manager, I'd say decisiveness. You can use the fanciest computers to gather the numbers, but in the end you have to set a timetable and act.