I usually walk through my dreams when I wake up (in my mind) step by step through every event I can remember. If you can't pull up events or know there are gaps, try to retain feelings from those segments, or from the overall dream, and then slowly look through the dream again. If you hold that feeling in place (don't move or open your eyes when you wake up, some shifting in bed to be more comfortable is okay.) then you should find even small segments coming to you easily.

At first it might just be bits, but over time you should be able to remember long segments, or even several dreams.

(Note: I drink a LOT of caffeine and I have no problems with recall or lucidity.)