There is a lot of literature about "what and how to do", but I can't find anything about "What and how to think".
What should I think about when I have space from actions, when walking, bathing, relaxing, etc. I want my thinking to be productive, it is quite chaotic now. Should I think about my goals, or next action, or making plan or something like this?
I'd like to read about this to form my "thinking system". Is there any books about this, or maybe general concepts?