George, for the most part, I don't. If there is some structure nearby, where I can sneak in and have a little elevation, I'll often try and pull the coyotes uphill out of the flats and that is often successful. The last coyote I got, last Sat. morning was a stand exactly like that. But I don't often just setup and call out on the thick flats. Lots of game in them, but I'm a firm believer in setting my stands up to stack the odds in my favor. I always strive for a setup where once a coyote commits to coming in, he is going to have a really hard time leaving. We are fortunate enough to have access to virtually unlimited public land here in our part of the country, so it's usually an efficient and effective strategy to simply roll on by those hard to hunt flats and find some easier pickings.
I do end up calling the flats occasionally though. Sometimes, the sign is so heavy, and topographic structure so far away, you just have to play the cards dealt in front of you. Ideally, I'll find an opening even if it means a long walk, usually a patch of cheat grass. When I do find an island of open in an ocean of flat sage brush like that, I'll set my Foxpro a couple yards into the brush on the upwind side, and I'll sit about ten yards into the brush on the downwind side. The idea being that coyotes have a strong tendency to utilize available cover to circle downwind, and that I'll catch one circling into my lap. It's worked often enough to give me some confidence in the technique. But, and a non-trivial "but", it's a very time consuming kind of stand to make. Generally involves a long walk both ways. And although it has been successful for me, it has also resulted in coyotes coming in and being able to leave often enough to leave me kind of non-plussed over all. These factors are what has led me to mostly just roll on by and look for more friendly terrain features down the road. I think that most of the time, rather than investing an hour or more on a brush stand like that, I'll kill more coyotes over all by driving for another half hour - forty five minutes and investing 20 minutes into a better looking stand on the other side of the valley or whatever.
I should mention too though, that sometimes out on those flats, I'll just plop my butt down in the brush with a very limited view and start calling, just hoping for the best. Tim and I call that a "brush stand". Often as not, the truck isn’t even hidden on those stands. If the sign is thick enough, you almost have to make them - it's just too hard to drive by really good sign. We call in coyotes on a high percentage of these stands. But our kill ratios on them are depressingly low compared to the kind of setups I prefer to make. Whereas over all, I usually end up killing about 70% of the coyotes I call in on most of the stands I make, it's more like 30% on brush stands. Just too easy for the coyotes to come in, bust me, and leave without ever offering a good shot.
Something I mentioned above, that pertains directly to the discussion of open vs. structure, that I think is worth fleshing out a bit more, is a coyotes tendency to utilize available cover to get downwind. It is precisely that coyote trait that has caused me to gravitate towards calling more open ground over the years. Now, I realize that all coyotes are different, and that there is no such thing as "always" or "never" when talking about coyote behavior. And I also realize that there is a world of difference in how a coyote living in a remote area will react to moving across open ground in daylight vs. how a a coyote living in an agricultural area will react to moving across open ground. All I ever hunt is public ground though. Rarely if ever do I hunt private ranches, and never farm country where the coyotes get shot at by every truck that drives by. So the coyotes I'm relating to obviously act different than the coyotes someone else in different circumstances is relating to.
So, anyway... It's been my experience, that if there is cover available that a coyote can use to circle downwind of the call, the coyote is very likely to use it. Where as, same coyote, same calling sound, but no cover, the coyote is more likely to just come straight in on a string. If that is true, and I strongly believe it is, then the advantages of hunting more open ground become obvious and significant. The more I came to realize and believe this, the more I started seeking more and more open ground to call. And eventually came to realize that I had been wasting a lot of time, getting busted on a lot of stands, calling in spots where there was good cover available for the coyotes to get down wind of me. My strategy and tactics have evolved to both avoid situations where the coyotes will have too much of an advantage due to this factor, but also to take advantage of their strong tendency to behave this way in situations where it comes into play. Like the "island" stands in an ocean of sage brush I talked about above. Or calling in timber or trees etc. I almost never make stands in this type of cover anymore unless I can find a setup that allows an ambush in downwind cover. Things are much simpler and easier calling open ground!