I'm not really an expert either, but I've seen more elk run away at the sound of a call than come in...unless I'm the only hunter there. I think they learn quickly in pressured areas the difference between a hunter and another elk. For one, I think most of the elk shut up when they start to figure out it's hunting season. This year I rarely called, and saw elk all over the place compared to the people who called more. I had an elk at 70 yards and it was looking like it was moving out of the area, so I had to do something and cow called. It quickly came into the meadow, looked in my direction and very quickly left the area (decoy might have helped that one). Unpressured, the elk would move on their usual travel routes. Once the "herd" of hunters came in with their cow talk and bull bugles, I saw nothing move. I had to go as far away from those pressured areas to find elk.
One other thing, I've had more elk run away as I tried to "sneak" up on them than when I'm just stomping down the trail, but the ones I saw as I was stomping down the trail were not in positions to be shot. Still have not figured a way around that one.
Best I can figure is either get lucky, or try to be where the elk are going to be and don't make a peep.