Methods for improving memory have a very long history. Perhaps the most ancient is the use of rhymes or stories to link a series of ideas. The classical Greeks and Romans developed their own mnemonic memory systems.
In general terms, mnemonic techniques involve learning ways of associating ideas to form patterns that make otherwise unconnected items more easily remembered.
Perhaps the earliest of these mnemonic systems is the Memory Palace or Method of Loci. This involves associating particular items that you wish to remember with specific locations (such as rooms, or areas in rooms) of a familiar house. You can then take an imaginary walk through the house to recall the items associated with these rooms and areas. This method can also be extended to outside areas (using landmarks, for example, on a familiar walk).
You can learn other important mnemonic methods by following the links shown below.