Final Step 
Repeat Steps 2–4 for every area of the image that you want to edit selectively. Fix the dark buildings on the left, darken the sky, and add definition to the clouds using more RAW Smart Objects. If you need to, go back and edit each RAW conversion to balance all of your picture’s elements, and adjust the opacity of your individual layers. This technique is very powerful, but you may want to save it for your most important images, not only because it takes patience, but because it takes lots of processing power; depending on the speed of your computer, you may have to wait a bit for the machine to catch up with your work.