One thing that helps me is being able to have all my materials for whatever I'm studying spread out around me. It's way more effective for me to study on my bed or on the floor or on a couch with a table in front of me than sitting at a desk or at a table in a chair. I usually have my textbook/s, notes, dictionary of biology, notes from related/prerequisite classes, and my computer spread out around me, plus any other materials. A bonus to having things set up this way is that it makes it a bit annoying to get up, so I tend to study longer. Also, if your notes/materials are mostly not on your computer, you can put it at the edge of your reach, and then the temptation to constantly go back to your computer to do something unrelated is reduced (for me at least).
For straight-up memorizing, I've done a LOT of experimenting on this, and by far the best way for me is to read something while listening to someone else/a recording of me reading it out loud. Sounds a bit odd, I know, but it is easily two or three times faster for me than any other method I've tried. Second best is reading things aloud to myself - not whispering, either, I mean talking in a stage voice. Third best tends to vary by what type of info I'm memorizing, but I have had some success at various points with flashcards, writing things out, making a list and then writing it in a different order, reading the same thing over and over, making mnemonics, setting things to music in my head (or out loud), making puns with the info, reading the same fact from several different sources (e.g. phrased differently, on paper and on computer, in different fonts, in different colors, etc.).
I also find I study best when it's not completely quiet, but there's no words in the noise. So, instumental music, ambient noise, birdsong, people talking too far away/quietly for me to make out words, etc. all help my concentration. I do know some people, though, who swear by earplugs to get them to focus.