I have about every call you can buy off the shelf, plus 40-50 custom made ones, electronic calls work great as well. Make sure you are where coyotes are..... siren before daylight works great if can't find visible sign, then approach your stand as if a coyote is watching you get into place, play the wind and then be persistent... They'll come, and there is fun to be had in the timber as well as wide open places....
Wind and careless noise is more important than ecaller or mouthblown in my opinion.
Good Luck, and learn to howl....