Watch your subject, not just your camera
We all do it. Digital cameras are especially to blame, luring us in with their dials, buttons and screens. These little computers demand our attention and feedback delicious, backlit, crisp images - immediately satisfying, in a way. Old fashioned manual film cameras too, have their own distractions. Have I focussed ok? Does that half a stop over-exposure matter? Can I get away with 1/30 second?
Especially with people shots, and others where the action unfolds in tiny fractions of time, we profit from paying most attention to the subject. Indeed this is a skill: you have to learn to do the jobs you need to (focus the thing, remember) in a fluid, almost unconscious manner, so that you can concentrate on what counts. We do this all the time when driving. I have no conscious recollection of my gear changes on the way to work this morning, yet all the evidence points to me doing it.
By concentrating you discern and select. For me, you are simply more likely to grab that special gesture wherein the whole image comes together and the picture made.