Photoshop Tip: New layers
Tips & Tutorials, by Mark White
December 30, 2012
A quick tip that could make the world of difference when retouching images in Photoshop
For retouching, make sure that you always add a new layer for each section of an image being edited.
New layers means they can be removed without damaging the image itself.
Try to never make changes to the Background layer (the first layer in the layer stack).