Every night before I go to sleep, I say, "Tell me what I need to know." Then I set the intention that when I wake, I will remember my dreams. In the morning, I wake knowing or understanding something I didn't before I went to sleep.
Of course, you may also need to understand some of the symbolism in your dreams and be willing to spend a little time analyzing the symbols or listening to what your intuition tells you about what was in your dream, but it is time well spent. Your dreams are there to guide you through your waking life, and intending to remember and understand them helps set this process in motion.
Want to know more about interpreting your dreams? Check out my book Dark of Night in the Light of Day: The Art of Interpreting Your Dreams.