/sci/ - Science & Math

/sci/, how do you properly take notes out of a textbook?

I am studying for my subatomic physics course right now - I have an exam on Wednesday and I haven't done any of the homework (it was optional) or gone to lectures yet. Our texts are Griffiths and Thomson.

I've taken a course in special relativity and quantum mechanics, as well as a PDE course, so I am confident I can make it though the material before the midterm.

But I know I am taking notes inefficiently. I can't escape the thought that everything is important, because why else would these authors include it? Obviously I should write down equations, and of course doing problem sets is the true key to learning, but how do you guys take notes/how would you approach this?