I understand that each adjustment can have its own mask to control how and where that adjustment affects the photo, and the is a very nice approach. But is there any way to do standard layers as well? For example, if I wish to replace a sky is there any way for me to add a new sky image and then cut out the current sky? Or use a gradient mask to allow a new sky to bleed through? Or use blend modes to have the sky added to the photo?
I believe all of those require a second layer. I understand that I can add an image layer but I am not sure that will function as a standard layer.