Around here, fox hang tight on fence lines as does the coyotes.
I make a modified dirt hole set usually with a large obstruction for backing and a step down about 2 inches deep for the trap. For bait or scent, I prefer mink gland over anything else. I found squirrel hair absorbs the odor quite well, so I cut a dried pelt into small pieces and store them in an incream pale with a mink carcass and crushed mink gland. Works great.
Here’s a typical area I look for. Just love this pic. Look where this grinner is caught at BTW, you can see how much the back rock is polished up from a few fox caught at this set.