Now we’re going to create a planet in a separate document. In this case we’re going to go with a 4,500 x 4,500px new document size. The first thing that you need is a good texture. Cgtextures.com has good images for this kind of task. We’ve applied the ‘SoilSand0165’ image. Add it to your planet document on a new layer. Duplicate and rotate it by 180°. Rearrange it so it’s nearly a square. Merge both texture layers and erase the hard edges with the Clone tool (S) where both parts met each other.
Activate the Elliptical Marquee tool (M) and make a circular selection from top left to bottom-right corner. Crop off the parts that you don’t need. Make a selection of the layer again and apply Filter>Distort>Spherize at 100%, Normal mode, twice. Now create a new black circle shape layer of the same size. Add a vector mask to this layer and apply a black-to-transparent Gradient tool (G) to delete the shadow on the dayside of your planet, creating shadow to the right.
Create a new black circle above the shadow. Apply a light blue Inner Glow layer style, set to Screen, 250px and Source set to Edge. Also apply a same colour Outer Glow with the Size at 55px and Range of 50%. Add a white Stroke of 6px Size. Set the entire layer to Screen blending mode. Create a new group (Cmd/Ctrl+G); this is needed to delete the atmosphere’s unnecessary parts. Add another mask to the group and use the Gradient tool (G) as before. You can now change the colours, etc, but basically you are finished.
Add the planet group to your scene right above your background layer. Adjust its colour setting and improve the shadows in order to make it perfectly fit into your scene. A second planet is always a good idea to improve the feeling of scale and to give more depth. Just repeat the steps and size down the new planet to 10% of your original one.
Now it’s time to add some more mountains. Open one of the mountain stocks and add it to the scene on a new layer below the other mountains. To make it fit into your scene you have to adjust the lighting. Press Cmd/Ctrl+U and set Lightness to +40. Change the Hue to a more yellow/red tonality. Now use Lasso tool (L) and cut off some parts to change the shape of your background mountains. A Gaussian Blur of a 1-2px Radius is the last thing to apply.
Next we’re going to add snowflakes in the foreground. Create a new layer above everything else. Now take a hard round brush, 2px in size, and make some random dots. Then press Cmd/Ctrl+T and transform it up to 400-500% of its original size. Duplicate the snowflake layer, transform its size by 125-150% and set the Opacity between 50-75%, then rotate it. Now merge both layers (Cmd/Ctrl+E) and repeat the step as often as you need to get the desired effect.
It’s up to you to add further elements to the image. For example, you can add a single house, some people, an old, dead and frozen tree or some kind of vehicle. Keep in mind not to overdo it. In this case it’s better to go with one additional element at the most. There are already a lot of details provided in the scene and the eye of the watcher only needs some focal points to follow. This is your scene, so have fun and add in your own elements as you wish.
As we have darker parts above the clouds, stars would be a good addition to the scene. Add a new layer just above your background layer and create a black square shape. Rasterize it, select the shape and add a Lens Flare as shown in the example. Select the layer again and apply a Radial Blur, setting both Spin and Zoom to 100%. Size it down to 15% for larger stars. Set the blending mode to Color Dodge. Duplicate this layer over and over again, changing the size and colour as you wish.
The final changes are basically done with fill and adjustment layers. Before you start this, add another layer above everything else and add more shadows to the foreground by using the Linear Gradient tool (G). Set this layer to Soft Light and change its Opacity to 50%. For this image, the adjustment layers that we will use are Color Balance, Hue/Saturation and contrast layers (Levels or Curves). Place them at the very top of your layer structure. It’s important to work with vector masks and all gradients style to achieve the intended look.