I used to set my alarm for 3 am, wake up just long enough to write down a few images from a dream, and go back to sleep. Then do the same when I woke up at my regular time. Then, when I had time during the day, by sitting quietly and thinking about the few images, slowly both dreams would come back. After doing this for several months, I could recall the whole dream immediately. I don’t recommend relying on drugs to heighten your dreams. I would be concerned that they might also distort your dream content. But anything you do to increase the blood flow to your brain will increase the vividness of your dreams. If you don’t meditate regularly, I recommend it. If you do, try imagining a bright light just above the top of your head, and with every deep, slow breath, the bright light flows down through the top of your head. This is an image that your subconscious mind will recognize and will relax the blood vessels in your brain, increasing the blood flow. Do this for a while as you are falling asleep, and your dreams will be more vivid, and if you persist, you will have more frequent lucid dreams (dreams in which you are fully conscious of being in the dream world). Jackm’s suggestion is a good one also. If you get in the habit of questioning yourself during waking time, you will start doing so while dreaming. If you ever ask yourself “am I dreaming” and are not sure your are awake, then you are asleep, and will start to dream lucidly. Also, look for clues that you are dreaming. I (and apparently a lot of people) have dislexia in dreams. If I have trouble reading, or if words keep changing as I am reading, I know I am dreaming. Lucid dreams are very vivid, and a hell of a lot of fun. But remember, anything you do in dreams has the same psychological effect on you as if you really did them. Also, I had a professor in school who stood on his head for ten minutes every morning and every evening. I have never tried that, but it makes sense.