Here are the factors that separate the pros from everyone else. When the amateurs have packed up and left, the pros are still glassing. When searching for game, the best hunters look meticulously before they give up on a chunk of real estate. They quickly scan the area, hoping to see an animal in an open, sunlit clearing, but know they're more likely to spot only an antler tine, a leg, or a rump patch in a shaded, brushy tangle.
Pros keep their mouths shut.
Big game animals have supersensitive ears. Unless it's an emergency, it's best to never talk in the woods, and then only in whispers. Shut up and see game. Pros move quietly. Modern life doesn't lend itself to silent walking.