PS Tutorial - Super Simple Dodge & Burn Method

Apologies for the crap framing. I had set the 6D up with WiFi but I’d framed it to me working on the computer - where I tend to slouch quite badly - and for some reason my posture was fantastic here, so it screwed it all up. I’ve seen various ways of dodging and burning, from using the tool straight on a photo, to using a gray 50% layer above and applying it there, to using the high-pass filter, but none of them allows the user to see exactly what they’re brightening and what they are making darker quite