Usually when I need to stay focused, I isolate myself (in a quite corner) with only a textbook and dry erase whiteboard. I like to draw things out with different colors. I'm a visual learner.
The computer distracts me too, so I like to get all my textbook reading done first before I use the internet for my assignments/quizzes (cause I know there will be more than one tab open! ...email...tasbeha...).
I'm not really a morning person, but by the end of the day I'm usually exhausted and distracted with a gazillion things! So I've found that one hour in the morning = 3 hours studying at night.
And finally, if you're a crafty person like me, then use your creative talents to help you study! Get out your crayons, construction paper, ribbon..etc to draw out the diagrams and charts from your text
My parents always think I'm playing around (and sometimes I am...) when they see me with crafts instead of a textbook on a desk like a normal student.
We all have different strategies and techniques to succeed, so evaluate yourself first: are you a visual, auditory, or kinesthetic learner? do you get more work done in the mornings or at night? what are some things that distract you the most? what are your talents? Then work from there!
Hope this helps a bit.