Tutoring an academic subject is almost pointless if the student has trouble concentrating or thinking clearly in general. Many students have difficulty learning because they (often unintentionally) do things that sabotage the learning process. The following document contains a summary of what I learned about improving my mental clarity, focus, and mental stamina while I worked on my B.S., M.S., and Ph.D. degrees in physics. I hope this is helpful for other people.
This is a very short summary. If you have questions, let me know!