Short term memory is about more than mere mnemonics. Mentally accenting your observations and experiences becomes a way of life.
Every occurrence is unique and special if, for no other reason than that it occurred to YOU. Mentally exaggerate your experience. If the experience isn't so "good", then concentrate on the sensory aspects instead of judging the conditions. This activity alone will skyrocket your enjoyment of your everyday world and assist in all creative memory endeavors.
Whole mind learning helps short term memory, making it easier for you to reap the benefits of self improvement.
Our brains evolved to code and interpret complex stimuli - images, colors, structures, sounds, smells, tastes, touch, positions, emotions and language. We use these to make sophisticated models of the world we live in. Our memories store all of these very effectively. Unfortunately information we have to remember is almost always presented in only one way - as words printed on a page. While language is one of the most important aspects of human evolution, it is only one of the many skills and resources available to our minds.
By coding language and numbers in striking images, you can reliably code both information and the structure of information. You can then easily recall these later.
You can do the following things to make your mnemonics more memorable and thus aid short term memory:
Use positive, pleasant images. The brain often blocks out unpleasant ones
Use vivid, colorful, sense-laden images - these are easier to remember than drab ones
Use all your senses to code information or dress up an image. Remember that your mnemonic can contain sounds, smells, tastes, touch, movements and feelings as well as pictures
Give your image three dimensions, movement and space to make it more vivid. You can use movement either to maintain the flow of association, or to help you to remember actions
Exaggerate the size of important parts of the image
Use humor! Funny or peculiar things are easier to remember than normal ones
Similarly, rude rhymes are very difficult to forget!
Symbols (red traffic lights, pointing fingers, road signs, etc.) can code quite complex messages quickly and effectively
Short term memory training could even prove fun. Try it.