I'm sure you all run into this when shooting. Between poses the subject smiles a certain way, tilts their head into the light just so, looks down, up, or flips some hair that fell...and yeah, THAT was, or would have been, an amazing shot.
I've learned to simply glance at the back of the camera once after a lighting change to make sure it's what I want. After that, it's keeping my mind and eye (and camera) focused on the subject ready to catch that impossible to plan shot. The one candid shot that really gives the viewer a glimpse at the real person. I use the words 'freeze' and 'stay' a lot. And I usually just give the subject some painfully general instructions on the pose. If the lighting is super critical I'll share on the back of the camera what the shots are going to look like so they can plan their looks to the lights. Other than that, as long as I'm not battling the DITH look (deer in the headlights) it usually goes very well.
I now average 400-700 shots in a 2-4 hour shoot. Some would still look at that as 'Spray and Pray' but it's not. I did that a lot when I was new so I know what that is. No control and you have no idea what you have when you upload. When I look at my uploads there are very distinct sets and multiple shots were trying to catch that smirk, wink, hair falling in the face, that shot that makes it real and interesting, or just fun. It gives the subject the freedom to play a bit in that set.
So, next time you notice you are spending a lot of time looking into the back of your camera, or sharing those shots with the subject, remember that you are loosing focus.