TWO RAWS MAKE A RIGHT: STEPS 1 - 3
1. Open your favorite RAW converter (I'm using Adobe's Camera Raw), and assess your image. Settle on the color, contrast, and saturation you like best. We'll be changing exposure but leaving the rest of the settings constant.
2. Adjust the exposure of your focal point first: In this case, the sky's more important. Move the slider left to decrease the sky's exposure and darken it. Ignore the land below; don't worry if it looks too dark-we'll fix that later. When you're satisfied, open the image in Photoshop. Save it as Sky.tif.
3. Then go back to Bridge (or your favorite browser) and open the RAW file to convert again. All your settings remain. Now slide the exposure right until you like the way the land looks. Open the image in Photoshop and save it as Land.tif.