Exercise for the mind has been shown to help memory, just like exercise for the body will help muscles! If you enjoy crosswords or sudoku, do them more often or play trivia games with friends. These activities will keep your brain functioning sharper and consequently improve and protect your memory!
Challenge your memory. Push yourself to remember small things. There are many games online and training programs that are specifically made to challenge and work your memory. Play them regularly so as to get into the habit of remembering. Your memory is like a muscle and like every other muscle it needs to be exercised.
A common trend today is something called "brain training" which is the equivalent of exercise for the brain. Give it a try to improve your ability to focus, remember, and solve problems.