Originally Posted by TheOtherDave™
Eliminate all distractions, then check off the topics you need to address one at a time.
Every 2 houra or so, take 10 minutes to stare at something other than your books.
Agreed except with me, I tend to focus in much longer intervals. It depends on my interest in the subject. I have finals in physics and circuits coming up, so I study by doing all the problems in the book that are relevant. This usually focuses me for 5-6 hours at a time.. Then I normally sleep or eat or something for 3-4 hours.