A number of years ago, I had a 5" wide elastic fabric sewn onto the ends of my DayOne Fleece pant legs. The elastic gets tucked and the pant stays out of the boot top. A nice fit that keeps the pant leg in place.
With my wool pants, I wear them outside the boot as that would be too tight. Can't find that 5" elastic fabric anymore or I'd do that to the wool too.
That being said, I find on occasion that under brush makes a scraping sound on my Lacrosse Burleys with the tucked pant, but the wool hanging out muffles that noise. Fleece or wool gaiters may be the best solution.