Regarding electronic calls, I bought a Primos call and it worked great for a time, but then the coyotes stopped coming to it. I've read that the electronic callers make sounds that are too repetitive and the coyotes eventually figure that out. I might have been using it too often. And at high volume, the less than most expensive electronic callers won't have quite as clear a call, which also might be a warning indicator to the coyotes. I don't know the above to be true, but it does go along with what I've experienced. A good mouth call or two or three just might be the best way to go.
And I got a coyote decoy. That worked great a few times. And I got one of those whirlygig deals with the furry tail. That worked great on Bobcats, but the coyotes didn't notice. The foam plastic rabbit decoy was ignored by everything that slinks or flies. I'd probably do better with one of those inflatable girlfriends, but then I'd have a pasture full of old ranchers.