One of the best memory aid is using the initial letters of a phrase or sentence or series of items to make a silly sentence:
The colors in the spectrum -- ROY G BIV ~~>red, orange, yellow, green, blue, indigo, violet
(There's even an art gallery in Palm Springs, CA, with this mnemonic as its name!)
The order of operations for math -- PEMDAS -- please excuse my dear aunt sally ~~>parentheses, exponents, multiplication, division, addition, subtraction
... and many others.
Think of some lists or phrases you need to memorize and then make up your own mnemonic.