My dad taught me a different one for the months, which entailed counting your knuckles and the space in between, starting with the knuckle or your index finger. The knuckles were for months with 31 days. The spaces for February and the months with thirty days. When you finished with one hand you started with the other. In doing this you end with a knuckle for July and then begin with another knuckle for August. It works!
My mother had one for all the French verbs that are conjugated with être.
Mrs RV Vandertramp.
Even knowing that, however, I'm afraid I can only come up with a few of those verbs. Maybe somebody with better French than I have can get them all.
As I understand it there are several different ones for remembering the planets, ordered by their distance from the sun. The one we were taught was for when Pluto counted.
My very educated mother just served us nine pickles.
And for students who take trig, of course, there is the famous Indian Chief
(sine is opposite over hypotenuse, cosine is adjacent over hypotenuse, and tangent is opposite over adjacent).
The one I liked the best relied on the shape of your mouth when saying the words. Abscissa has to be for the x (horizontal) axis because your mouth is horizontal saying the word. Ordinate has to be for the y (vertical) axis because your mouth is vertical saying it. Though I must confess that as much as I like the memory device, the knowledge is pretty useless. Apart from that course on analytic geometry, I don't recall ever using these words.
I am usually down on rote, but I was able to recall each of these without looking them up. (The spell checker got me on abscissa, where when I initially tried it I omitted the first "s".) One reason to be down on rote is that "the knowledge vanishes through the students' fingers as they write the final exam." This is a line from a former colleague in the Accounting Department, Dave Ziebart, specifically in reference to students (not) understanding discounted present value. Business students are exposed to the concept in several different courses, yet most don't really get it. Contrast that with the mnemonic devices I was taught. Once learned they stay learned. That's the part I'm scratching my head about. Is there something special about the mnemonic devices?
One thing I did have to look up in writing this piece was the spelling of mnemonic. I began with a word that looked something like pneumonia. Thankfully, some Google searches have a phonetic basis. Just because you start out wrong, it doesn't mean you have to stay that way.