The big caveat and danger with using photos like scans is that you HAVE to make sure your photo is a high quality, and use natural lighting to get it as flat as possible before interfering.
I made this tutorial because I realised suddenly that the feather tool in Procreate is absolutely perfect for unevenly lit photographs of work. So when using curves will bleach one half of an image while leaving the other still too dark, you can use a smooth gradient of selection to play with images in halves.
SEASIDE ILLUSTRATION 