...diagnostic questions...

Time-use does improve with practice. But only constant efforts at managing time can prevent drifting. Systematic time management is therefore the next step. One has to find the nonproductive, time-wasting activities and get rid of them if one possibly can. This requires asking oneself a number of diagnostic questions:

1. (...) What would happen if this were not done at all? And if the answer is, Nothing would happen, then obviously the conclusion is to stop doing it. (...)
2. The next question is, Which of the activities on my time log could be done by somebody else just as well, if not better? (...)
3. (...) Effective people have learned to ask systematically and without coyness, "What do I do that wastes your time without contributing to your effectiveness?"

The Essential Drucker
Peter F. Drucker
Collins Business (2005)