Replying to Help Installing Elastic Cinch in Pants

Recently got big strides and they are a bit too big. Cuff gaiters and outer shell of the pants sags down underneath the heels of my boots and I know that shit is gonna get chewed up in a couple days of hiking or walking in the parking lot.

I remember reading a thread where some guy put elastic cinches in the cuffs of his pants but I can’t find it in search. Anyone got experience with this or could give me tips? I’m pretty good at sewing/have access to a sewing machine and crafts store.