Using Gradients

I've experimented just a bit with gradient layers.  I know they are a great tool for coloring a photo when accompanied by manipulation of the layers.  Let me show you a before photo. . . . . this pic was taken in Sedona, AZ on a cloudy day.

I began the transformation by duplicating the layer and then changing it to "multiply".  The intensity of the photo changed instantly and I merged it down.  After that I added a gradient layer called "rust, green, gold" and changed the layer to "saturation".  That's it.  A completely different and more beautiful photo than the original.