I think I'd rambled about this before, but here in Southeastern Nebraska there isn't much for "open terrain" and every coyote line I've ever ran I regularly take nearly the same amount of coons in the same sets. Little creeks, old pastures, fields, etc. didn't matter about the location. On a bright note, the coons I did get out in the open at my coyote sets tended to be on the large side consistently.
I haven't found many lures or baits that aren't interesting to coons, and conversely I catch a lot of coyotes and fox on bait made from fish or fish oil squirted down a dirthole.
If I consistently want to target coons on dryland sets though, I have to change the set a little. More eye-appeal (big dirthole, big dirt pattern, etc.) and then I either use a very large backing or no backing at all. Coons love to stand on top of the high spot and reach into a hole to steal a bait, and you have to force them around over your trap.
Bedding is way more important to me for coons than for fox or coyotes, too. If it moves, coons will fish your trap out of the bed, flip it over, and often you find the trap either set off or flipped out of the bed but unfired.
But as for lure or bait, If it works on canines, it will be great for coons. Later in the year, good coyote or fox gland lure is hard to beat for either. I've caught a lot of coons on nothing more than a post set squirted with red fox urine. The post set had very little eye appeal, and coons don't pee on posts to mark territories like canines do. The only appeal to those completely blended in post sets was the red fox urine. My favorite coon/fox combination set is a double dirthole, one hole dug nearly straight down, and other at a very shallow angle. One hole is small, the other is large. The little hole gets fish bait, or a loud red fox gland lure...and the other hole has a piece of sheeps wool or cotton ball soaked in red fox urine in the bottom of the hole with some wadded grass over it. There's a million variations to that set, but that basic set has accounted for more coons and fox for me than any other set combo I use.
Even loud, raunchy coyote bait has appeal to coons, too. Bobcat gland lure and mink gland lure are also killer coon lure and fox lures for me.