I don’t have one, my number system only goes from 00 to 99. If I needed to remember that I would see Mare (from overlord) eating a trash can.
My number 3 is Mare playing the piano, my number one is Kalameet (from Dark Souls 1) eating a trash can. So, applying PAO to 3,1 and 1 gives me that image.
I don’t use fixed mnemonics (except for some numbers in the 0-99 range), but might use “muted”, like someone talking on Zoom but they forgot to unmute. Or matted like @iOSDeveloper’s example; that’s nice.
What do you mean “in the beginning”? It’s not as if mnemonics will make it so you can just recall numbers on their own, if you chose to practice mnemonics you’ll use those systems pretty much forever.
In the beginning I mean, when you just chose the image… once you have it set in your brain, it doesn’t matter what system you used to choose the image if any.
I remember one of the first books I read on mnemonics (either Harry Lorayne or Tony Buzan), they mentioned that after some time, the line between a “mnemonic memory” and a normal declarative memory blurs and fades away after time. The idea was to use mnemonics to get information more easily through the door to your long-term memory, but if you frequently rely on a piece of that information, eventually you won’t need to think of its image anymore.