Maybe, you guys may point out how do you increase your focus to study effectively while study.
Well Jerry, I sometimes have this problem too. I find that sometimes after a hard day in school, my mind tend to drift away when I start to study. Or when I have so many things in my mind and things are starting to get very overwhelming, my mind would start to linger around. Maybe you are one of the people who are easily affected by noise. Since you mentioned that noise affected you, try to find a time where it's quiet around so you can study better, like during the time you get up in the morning: 4am or so.
Being able to study is also greatly contributed by being in balance in life. By balance, I mean by balancing leisure time with school time. Having all work and no play may affect you for it certainly affect me. Having enough sleep and rest plays an important part to your ability to study during the day. Studies have shown that students with more REM sleep are able to function better than students with less REM sleep. It also depends on how motivated you are to study at that time. And also try not to study one subject through out the day for it would only make your studying dull and repetitious. It has been proven that students do better in exams when breaking down the subjects they study rather than mass studying a subject.
Sometimes, my major problem lies in the moment to begin to study. So I try not to overwhelm myself by studying a hard subject first, but rather, study for an easy course, just to try to keep the ball rolling and then later, I would find myself so engross in studying that I start to make plans ahead on which courses I will study. I priortise them by level of difficulty: I study the most easiest course first then save the hard one for last. Try to add a motivating factor or a reward for yourself after you have completed your studying.
If you are tired, by all means, sleep. I find myself being able to study better if I sleep for 8-9hours a day. And if I have been up and going since 6am till 4pm and follow up with some physical activity for 3 hours straight , I wouldn't be able to study so sleep would definitely be my first priority.