What worked for me to increase cadence was to use a trainer.
Pedaling on a trainer with my bike computer displaying cadence really helped me to get into the habit of being at least 80 RPM all the time.

After that, I concentrated on the bottom portion of the pedal stroke - imagine scraping mud or gum off shoe every pedal stroke.

I have trouble pulling up on both feet. I haven't found a good suspension method for my artificial leg that lets me use the same force on both legs. I bounce on saddle when my cadence gets around 110 RPM because of that unevenness in my pedal stroke.

Two-legged people can use a trainer to do single-leg drills to help themselves pedal in circles.