It is fun to experiment with different coyote sets. Each type of coyote set has different variations of the same set. For example, there are at least four variations of the dirt hole set. There is the 45-degree dirt hole, the straight dirt hole, the twin dirt holes and the large dirt hole. I am sure there are other variations that other trappers have come up with.
As far as flat sets, there are too many ways to make them to list. All trappers have their favorite sets and most trappers, including myself, usually stick with what works for