In addition to exercising your brain, there are some basic things you can do to improve your ability to retain and retrieve memories:

1. Pay attention. You cant remember something if you never learned it, and you cant learn something that is, encode it into your brain if you dont pay enough attention to it. It takes about eight seconds of intent focus to process a piece of information through your hippocampus and into the appropriate memory center. So, no multitasking when you need to concentrate! If you distract easily, try to receive information in a quiet place where you wont be interrupted.
2. Tailor information acquisition to your learning style. Most people are visual learners; they learn best by reading or otherwise seeing what it is they have to know. But some are auditory learners who learn better by listening. They might benefit by recording information they need and listening to it until they remember it.
3. Involve as many senses as possible. Even if youre a visual learner, read out loud what you want to remember. If you can recite it rhythmically, even better. Try to relate information to colors, textures, smells and tastes. The physical act of rewriting information can help imprint it onto your brain.
4. Relate information to what you already know. Connect new data to information you already remember, whether its new material that builds on previous knowledge, or something as simple as an address of someone who lives on a street where you already know someone.
5. Organize information. Write things down in address books and datebooks and on calendars; take notes on more complex material and reorganize the notes into categories later. Use both words and pictures in learning information.
6. Understand and be able to interpret complex material. For more complex material, focus on understanding basic ideas rather than memorizing isolated details. Be able to explain it to someone else in your own words. 
7. Rehearse information frequently and over-learn. Review what youve learned the same day you learn it, and at intervals thereafter. What researchers call spaced rehearsal is more effective than cramming. If youre able to over-learn information so that recalling it becomes second nature, so much the better.
8. Be motivated and keep a positive attitude. Tell yourself that you want to learn what you need to remember, and that you can learn and remember it. Telling yourself you have a bad memory actually hampers the ability of your brain to remember, while positive mental feedback sets up an expectation of success.