First thing I'd recommend as take a wrist watch and set it off at 4.5 hours, and 6 hours after falling asleep, and then waking up giving you 3 chances to recall your dreams at 4.5 hours after you fall asleep you will start your 3rd rem period of the night, and your 4th being at 6 hours past falling asleep.

Rem is when you dream, try waking up inbetween a REM cycle for even better results