Photoshop Elements :: How To Move Elements Of Painting To Separate Layer

I would like to move elements of that painting onto a separate layer.   What is the best way to do this?   An example of this would be a painting with the moon in a night sky.   I might want to move that moon object into a separate layer.
 
My reason for wanting to do this is I want to change the background of the painting without worrying about doing fine details around the objects I am moving. A second benefit of moving the objects to a layer is that I can then easily move the location of those elements in the painting around, trying to reposition them.
 
can I get all of the elements I am moving onto a SINGLE layer AND still have the ability to move those elements around separately?  If I want to move 10 elements in a painting to a separate layer, it is REALLY inconvenient to have to put those into 10 separate layers and constantly maintain naming of these different layers.