It sounds like a strange concept, but the reasoning behind it is sound, and it is straightforward and easy to do. This excellent video tutorial will show you how to edit your photos in reverse and why it will help you make better and more precise photos.
Coming to you from Anthony Morganti, this great video tutorial will show you the ins and outs of editing your photos in reverse. If you work in Lightroom or any program with a similar layout, you probably start with basic global adjustments like exposure, highlights, shadows, etc., then move on to more local adjustments. And while that works fine for a lot of photos, if you are anything like me, you probably notice that often, once you make some of the local adjustments, you have to go back and refine the global adjustments because they throw the overall image out of balance. Morganti's method of starting with the local adjustments put them in balance first so that when you make the global adjustments, you maintain the relationships between different elements, reducing your workload and making the edits easier. Check out the video above for the full rundown from Morganti, and give it a try!
One interesting thing about this video is that he crops the image first, before doing his masking and reverse editing. I always crop as the very last step.
I have been using this approach to image processing for many years when I switched from LR to CO. At the time of LR6, CO already had layers (masks). With this workflow, I still reach my goal more efficiently and faster with optimal exposure than with the standard workflow.