Experts agree that if you do only one thing to improve your memory, getting more sleep should be it. “Sleep is key time for your brain to solidify the connections between neurons,” says Barnard. In a study published in the journal Sleep Medicine, researchers asked subjects to perform some memory tasks and then either take a nap or stay awake. The people who napped remembered more of the tasks they had performed than did those who stayed up. Rule of thumb: Get seven to nine hours of sleep total each day. And, yes, naps count.