Eliminate things that can interfere with clear thinking.

Avoid illegal drugs and excessive alcohol, which can impair both short-term and long-term brain functioning. Avoid excessive caffeine intake, which can interfere with concentration. Other simple steps you can take include getting enough sleep (about 8 hours is the right amount for most people), getting regular exercise, taking periodic stretch breaks when studying for long periods, and drinking plenty of water (about 8 glasses per day).