I think Elknut has some excellent videos (boring as hell) but excellent videos telling you what calls are what, and what you are saying when you are calling. If you don't know how to use it, then leave it at home is pretty much the theory I've heard. I can do a bit of a location bugle and some cow chirps/whines, etc, but I'll never be an expert. I think the other thing that must be taken into effect however is how many times those elk have heard calls before, and if they are "mute" elk, then they may likely head for the hills if you start calling at them. Not sure what this herd is like, but I'm going to be more inclined to keep quiet as well.