Hard to critique success. But I'm going to anyway. Even though I have never shot a coyote, I've seen it done on TV.

Actually a buddy of mine hunts fairly regularly and he advises on erring on the side of less calling over more. Most importantly, never call when the coyote is looking in your direction since their eyesight is so good. The idea is for them to approach the general area where the call is coming from without knowing the precise location.

Take this advice as worth what it cost you.