How to save versions of your Photoshop work using the Layer Comps palette
Very much like Snapshots in Photoshop, however the advantage of using Layer Comps instead is that they are kept even after closing the image.
Go to Window>Layer Comps and inside the palette click on the Create New Layer Comp button at the bottom.
You can name each ‘comp’ layer and jump back to one at any point, remembering which settings, colour, adjustment, etc. were used.