Gain more power and control in photoshop by mastering layers
The use of Layers is consistently the most feared part of Photoshop. I've had photographers tell me that they just can't deal with Layers, and I know very good photographers who do excellent Photoshop work, but still believe they "aren't ready for Layers," or "don't really need Layers" or even "just can't do Layers."
Yet Layers is one of the most valuable features in Photoshop. Once you start using Layers with confidence (and anyone can), you'll never go back to not using it. Layers can help you bring out the best in your photograph, and believe it or not, can be accomplished faster than not using Layers, plus with much more control.
Additionally, Layers offers the chance for the photographer to isolate key parts of the adjustment of an image. That means you can change one element without affecting anything else, plus you can put layers together in such a way that they interact with each other for even more control.
Keys To Understanding Layers
Every photographer really has seen layers at work. Your mouse on a mouse pad over the desk is a set of three layers: the mouse, the mouse pad and the desktop. You can't see the desktop under the mouse pad, nor the part of the mouse pad that's under the mouse. You look from top down and see whatever is on top first.
Or consider a pile of photos. It's another set of layers. You know you can move each photo separately, move them up or down in the stack, rotate them and so forth. You can remove any or all, add new ones and play with the group.