This photo is a blend of two different exposure settings. The original was a RAW capture that was processed (developed) in RAWShooter Pro so that there was a good setting for the sky area and another good setting for the foreground. For the sake of this tutorial you will see some exaggerations - as you see above in the trees on the right. You do not need to begin with a RAW capture. Begin with an image that either needs a darker sky area of a brighter foreground area. Use the histogram adjustment setting to make those adjustments and save one that looks good for the sky and another that looks good for the foreground. Don't do any cropping yet. Keep the two images you will need exactly the same size. In this case I had a sky.jpg and a foreground.jpg