A painter at a shop in Reno showed me how to read a dent with a flashlight, and it fixed my worst habit
Honestly I used to chase dents by eye and end up with a wavy panel every single time. Last month I was at a shop in Reno helping a guy on a 2016 Camry with a nasty crease in the quarter panel, and he handed me a plain flashlight. He taped a piece of cardboard to the lens so it made one thin line of light, then swept it across the metal at a low angle. The dent showed up like a map, and I could see exactly where the high and low spots were instead of guessing. I still do the tape trick on almost every panel now because it takes about 30 seconds. Ngl it saved me from sanding way too much on the last two jobs. Has anyone else picked up a cheap trick like that from working next to somebody?
A guy named Dale at a body shop in Sparks did the same thing with me but he used a strip of masking tape on the lens instead of cardboard. I keep a little flashlight in my toolbox now and use it on every panel before I touch sandpaper. It's crazy how much it shows that your eyes just miss.