first of all go somewhere where theres no distractions!
i find at home il just put off revision and spend the day eatin..watchin tv..sleepin..n waste time on pc

not gud!
so yeah..librarys the one for me..silent study all the way! n then i jus write stuff out ova n ova n ova agen..hilight main bits n then write again lol..borin bt it works!
Also try n think of rhymes n stuff or stupid ways of linkin info u need to knw or equations etc..that tends to help too.
gudluck wit ur exams!!