If you want better results while studying, revision is the key. Repeated revision consolidates the information in the brain and helps to retain the information. Other than that, try a daily exercise of recalling your entire day in as much detail as possible before you sleep. Initially only important or superficial details are recalled, but with practice minor details can also be recalled. Be more organized; make lists. Use acronyms and mnemonic devices to help you remember.
Take 45 minute slots followed by a 5-15 minute break. Eat and at proper times. Drink plenty of water. Find time for exercise or meditation
. Keep time for proper revision at end of study session. Revise before you sleep.