I mostly use snares also but right now the coyotes are mating and that means they’re making pee posts everywhere so what I do is plant a trap at every good spot they mark along my skidoo trail. I use drags wax paper sift all disturbances with snow make foot prints with a soda bottle and usually add quite a few yotes to the pile this way. 6 so far like this.

If you are asking just about fox, there is a set we used to use with effect in the mound set. This will take some work, but remember we were using these on location travel ways as you said this is mating season and fox are on the move, who have experienced all the pressure.
For mounds we used dry chicken manure. I have made these small as ant hills and large as you want to waste time with. The size is the attraction though and canines will on travel ways run on top of these.

If legal you can use old muskrat houses cut off and moved to travel lanes. If you have wind these mounds will blow free of snow and the dark color always contrasts with snow.

Place a 2 x 6 block on top and set on that, trap cover, and carefully use the duff. Staple this to a post as a drag, as you do not want the fox destroying the mound. You can use the post as big guide stick.

I prefer a call lure not on the mound to get the predators close, and you can use a matrix or gland lure on the post. If you have a big enough pile, you can set on the side too with a scent post, same set up of a drag pole.
Feathers help flutter and attract attention as much as directing toward the trap.
You can always use filler like bale or even a debris mound, and put the duff on top of that to save resources. Back in the day the trappers used to for January recreation have a couple of these working on hills in view from their porches or barns as they were easy to check.
Best to use a larger trap, offset in these sets.

Hope that helps.