Easy to make with durable Spandura from owfinc.com or less durable spandex from anywhere. Look at stretch gaiters at REI for the shape and sizing. I sew mine shut on the contoured front seam and just pull them on with my socks, Dirty Girls style. Coat hooks from any sewing store work well for gaiter hooks, but owfinc has gaiter hooks if you prefer. To keep them from riding up just stitch a loop of the stretch fabric on the inside of the gaiter above your shoe sides. It will fit under your foot. No need for velcro. You may need to make a couple to get it right.

That is for low to mid boots, but if you are postholing,you may need to use velcro to keep them down.