If I were to learn mnemonics again I would create a number-rhyme system for 1-99.
I’ve been using the Major system for 25 years and when I read numbers I quickly see images associated with each number. Unfortunately, I am very slow verbally because my mind has to hear the number, visualise it, translate it into phonetics, and recall the image.
It has just occurred to me that a number-rhyme system would be much faster. I hear the sound and the image follows immediately. No translation. The image is tethered to the sound.