[Question] What are some good resources on workflow or productivity for mathematicians?

I recently read Getting Things Done and found it to be quite helpful, and I’m in the process of refining its recommendations to my own needs (soon to start a PhD, trying to learn lots of maths, aiming for a career in research). I’m sure plenty of intelligent people would have plenty of wisdom to share on the topic, but a quick google hasn’t turned up anything great. Can anyone recommend some good books or posts?