In the early 1900s J W Dunne realised that he was having dreams that later seemed to come true. He theorised that our dreams are actually a 50 50 mix of past and future events. However dreams are lost so quickly on waking that a proper method needed to be employed. This system would help to notate them for proper analysis. His belief was that once you can remove what has already happened then what is left should be future events. He allowed a 2 day buffer period to see if they happened but major events were given a longer buffer. For example a cat running across your path would be 2 days and a natural disaster you might allocate 2-4 weeks. This excerpt from his book is his method for remembering dreams. An invaluable aid if you are in the habit of keeping a dream journal.
The dodge for recalling the forgotten dreams is quite simple. A notebook and pencil is kept under the pillow, and, immediately on waking, before you even open your eyes, you set yourself to remember the rapidly vanishing dream. As a rule, a single incident is all that you can recall, and this appears so dim and small and isolated that you doubt the value of noting it down. Do not, however, attempt to remember anything more, but fix your attention on that single incident, and try to remember its details. Like a flash, a large section of the dream in which that incident occurred comes back. What is more important, however, is that, with that section, there usually comes into view an isolated incident from a previous dream. Get hold of as many of these isolated incidents as you can, neglecting temporarily the rest of the dreams of which they formed part. Then jot down these incidents in your notebook as shortly as possible; a word or two for each should suffice.
Now take incident number one. Concentrate upon it until you have recovered part of the dream story associated therewith, and write down the briefest possible outline of that story. Do the same in turn with the other incidents you have noted. Finally, take the abbreviated record thus made and write it out in full. Note details, as many as possible. Be specially careful to do this wherever the incident is one which, if it were to happen in real life, would seem unusual; for it is in connection with events of this kind that your evidence is most likely to be obtained.
Until you have completed your record, do not allow yourself to think of anything else. Do not attempt merely to remember. Write the dream down.
Waking in the middle of the night, I have several times carefully memorized my preceding dreams. But, no matter how certain I have been that those memories were firmly fixed, I have never found one shred of them remaining in the morning. Even dreams which I have memorized just before getting up, and rememorized while dressing, have nearly always vanished by the end of breakfast.
It will be impossible, of course, for you to write down all the detail. To describe the appearance of a single dream-character completely would keep you busy for ten minutes. But write down the general detail, and all uncommon detail. Memorize the remainder by reading through your final record and attentively revisualizing each picture described therein; so that, should one of these unwritten details subsequently prove important, you can be satisfied that you are not then recalling it for the first time.
If, on waking, you are convinced that you have not dreamed at all, and cannot recall a single detail, stop trying to recollect the dream, and concentrate, instead, on remembering of what you were thinking when you first awoke. On recalling that thought, you will find that it was consequent on a dream, and this dream will immediately begin to return.
Read your records over from their beginning at the end of each day of the experiment.
Excerpt From: Dunne, J.W. “An Experiment With Time.”