(Study of layers without selections)
This is the original JPEG image (original size also)
(This is a shot of a recent train crash in Belgium, the driver was killed, his nickname was Tonio.)
The following images started from the one above, trying different layer compositing methods
opening some of them in new layers as a new source image, playing with the opacity settings.
Some work with different brushes and actions was added also.
(Click on red diamonds to enlarge images.)