Don't let tactical diligence overshadow strategic laziness. Do not repeat at a low level. Any task can be divided into two parts, the relatively easy part and the relatively difficult part. A reasonable schedule should be like this: Do the easy parts quickly, and put the time saved on the difficult parts. Don't waste a lot of time on the simplest things, spend 20% of your time solving easy problems, and spend 80% of your time thinking and researching difficult problems. Rather slow at a high level than repeat at a low level.
Recommendations on the Following Popular Books on <Time Management>
Getting Things Done: The art of stress-free productivity
Deep Work: Rules for Focused Success in a Distracted World
Expect Less from Yourself, Get More from Him, and Flourish at Work & Life