The best way to improve your memory if you're studying, is to add structure to what you're attempting to learn. Categorizing and taking things one step at a time, will allow you to learn and to retain the knowledge of a previous subject, before you move on to the next. This is undoubtedly the best way to study. We are more likely to remember something that happens to us when we are around other people than when we are alone. People are drawn to others, as a result we remember our time with them, rather than when we are alone. That's why study groups work so well.