For this image I wanted to experiment with changing daytime images to a night scene. I don't believe I have ever seen a blue scenery for real, but I like how it turned out just the same.
After photographing my base images with a Nikon D2x Digital Camera, I began masking them in Photoshop, a task made much quicker with greater flexibility and accuracy using a Wacom Intuos 3 Tablet and Airbrush pen.
The Deer photo is actually some miniature toys I borrowed from my daughter, and before flattening them onto the scene, I isolated then also using a mask, and created their shadow by duplicating that layer, filling their shape with Black, Applying a Gaussian Blur, then flipping vertically and using Photoshops Distort tool to elongate their shape to follow the direction that the moon might cast their shadows. Next I changed the shadow layer properties to Overlay mode and reduced the layer opacity a tad. If I recall correctly I may have done the same for the large tree and flattened these objects onto my background scenery. To get the blue effect, I duplicated the layer and used Colorize in the Hue/Saturation adjustment interface to pick a deep blue color, and darkened it by changing Lightness to -90. Next I made use of the Photoshop default Render Filter, Lighting Effects, and used an OMNI BLUE to lighten the sky and ground somewhat.
The rest was fiddling around tweaking areas until I got the look you see here.