Tom, the thing is that, as we move our leg up, that cuff bottom rides up a bit along the calf, and as we move the ankle down, it may ride down again. So you need something elastic that is tight at the top of the pedal stroke.

Tight-rolling the pant cuff like we did in the 80s is one way. ("pleat and roll" as one member said above) I remember having to buy pants 2" too long...

You might like a slap strap, but IME, they don't work well with a lot of pant cuff, like I have on cargo pants. I lost a set of pants that way when the slap strap let go and my mid-drive eBike (powered crank) ingested the cuff and ripped the hell out of it.

My favorite two are a simple reflective velcro strap with elastic section and an LED one with a buckle & elastic. It has 3 modes: on, off and blinking. You could use it on blink for walking and on for cycling. Wear on the arm or leg. Tighten to your preference, as it's adjustable:
https://www.planetbike.com/brt-strap...EaAspLEALw_wcB

The tried-and-true sock tuck is always an option too. I wear out the socks at the heel and balls of my feet well before I stretch out the top from tucking pants in.