The Greeks so worshipped memory that they made a goddess out of her — Mnemosyne. It was her name from which was derived the current word mnemonics, used to describe memory techniques such as those you are about to learn. In Greek and Roman times, senators would learn these techniques in order to impress other politicians and the public with their phenomenal powers of learning and memory. Using these simple but sophisticated methods, the Romans were able to remember, without fault, thousands of items, including statistics relating to their empire, and became the rulers of their time. Long before we had discovered the physiological breakdown of the functions in the left and right hemispheres of our brains, the Greeks had intuitively realised that there are two underlying principles that ensure perfect memory:
1. Imagination
2. Association
Whereas, in current times, most of us are actively discouraged from using our imaginative abilities, and consequently learn very little about the nature of mental association, the Greeks emphasised these two foundation stones of mental functioning and opened the way for us to develop the techniques even further. Quite simply, if you want to remember anything, all you have to do is to associate (link) it with some known or fixed item.

The Rules:
The rules for perfect memory laid down by the Greeks fit in exactly with the information recently discovered about the left and right brains. Without a scientific basis, the Greeks realised that in order to remember well, you have to use every aspect of your mind.
In order to remember well, you must include in your associated and linked mental landscape the following:
=> Colour:
     The more colours you use, and the more vivid they are, the better. Using colour alone can improve      your memory by as much as 50 per cent.
=> Imagination:
     Your imagination is the powerhouse of your memory. The more vividly you can imagine, the more      easily you will remember. Sub-areas within imagination include the following:
     ~> Expansion:
          The more gigantic and enormous you can make your mental images, the better.
     ~> Contraction:
          If you can clearly imagine your picture as extremely tiny, you will remember it well.
     ~> Absurdity:
          The more ridiculous, zany and absurd your mental images are, the more they will be outstanding           and thus the more they will be remembered.
=> Rhythm:
     The more rhythm and variation of rhythm in your mental picture, the more that picture will weave      itself into your memory.
=> Movement:
     As often as possible, try to make your mental images move. Moving objects are usually      remembered better than still ones.
=> The Senses:
     Tasting,Touching,Smelling,Seeing,Hearing
     The more you can involve all your senses in your memory image, the more you will remember it.      For example, if you have to remember that you have to buy bananas, you stand a far better chance      of not forgetting your task if you can actually imagine smelling a banana as you touch it with your      hands, bite into it with your mouth and taste it, see it as it is approaching your face, and hear      yourself munching it.
=> Sequencing and Ordering:
     Imagination alone is not enough for memory. In order to function well, your mind needs order and      sequence. This helps it to categorize and structure things in such a way as to make them more      easily accessible, much in the same way as an ordered filing system allows easier retrieval of      information than if that same information were simply dumped randomly on the floor.
=> Number:
     To make ordering and sequencing easier, it is often advisable to use numbers.
=> Dimension:
     Use your right-brain ability to see your memory images in 3-D.

Key Memory Image Words:
In each memory system there is a Key Word. This word is the 'Key Memory Word' in that it is the constant peg on which the reader will hang other items he or she wishes to remember. This Key Memory Word is specifically designed to be an 'Image Word' in that it must produce a picture or image in the mind of the person using the memory system. Thus the phrase 'Key Memory Image Word'.
As you progress through the increasingly sophisticated mnemonic systems, you will realise the importance of being sure that the pictures you build in your mind contain only the items you want to remember and those items must be associated with or connected to Key Memory Images. The connections between your basic Memory System Images and the things you wish to remember should be as fundamental and uncomplicated as possible:
=> Crashing things together
=> Sticking things together
=> Placing things on top of each other
=> Placing things underneath each other
=> Placing things inside each other
=> Substituting things for each other
=> Placing things in new situations

By now it will be clear to you that the systems worked out by the Greeks, and for nearly 2000 years discarded as mere tricks, were in fact based on the way in which the human brain actually functions. The ancients realised the importance of words, order, sequence and number, now known to be functions of the left side of the brain; and of imagination, colour, rhythm, dimension and daydreaming, now known to be right-brain functions.

Mnemosyne was to the Greeks the most beautiful of all the goddesses, proved by the fact that Zeus spent more time in her bed than in that of any other goddess or mortal. He slept with her for nine days and nights, and the result of that coupling was the birth of the nine Muses, the goddesses who preside over love poetry, epic poetry, hymns, dance, comedy, tragedy, music, history and astronomy. For the Greeks, then, the infusion of energy (Zeus) into memory (Mnemosyne) produced both creativity and knowledge.

They were correct. If you apply the mnemonic principles and techniques appropriately, not only will your memory improve in the various areas, but your creativity, your overall mental functioning and assimilation of knowledge will accelerate at the same fantastic pace. In the process you will be developing a new and dynamic synthesis between the left and right side of your brain.

Reference:
=> A Guide to Memory Increase by Rocco Oppedisano.