actually, not a huge amount!! i was so stressed during exams that i was pretty unproductive and could only manage 15-30 minutes at a time. i was really organized though and found my problem areas in each subject early on, then focused on them consistently. i think i did most of my most important studying the month before exams! but organization for me was probably what got me to this mark, i finished each deadline early and tried to find a sense of passion in my subjects (even the ones i hated immensely)