The whole problem with present day time management is that most work environments demand you to perform a variety of tasks simultaneously. In other words you have to multi task. Multi tasking is not natural to humans. That causes the whole problem. The first problem with multitasking is that one does mediocre work. But one is afraid of doing mediocre work. Therefore one is in a perpetual dilemma about how to work. The solution is to do mediocre work only. Divide your work into two types. One for which mediocre is acceptable and one for which it is not. For which it is not, set aside large chunks of time when you can do them at a stretch with freedom.