Painting the ground

The ground and mountain range were quickly sketched in using dark colors, all on the same layer. To get a hint of the sun's glow peeking over the mountains, load a selection from this layer, make a new layer, and fill it with a color, any color. The important step now is to lower the Fill to 0% and check the Layer Mask Hides Effects option in the layer's Blending Options. Add an Inner Shadow as shown, then use a radial gradient on a mask to reduce this effect to just where the sun is. I have used this same technique over and over in my work, as you can see from previous tutorials.

A second row of more distant mountains will make things a bit more interesting, so I painted some on a layer under the existing mountains. This was done with lighter colors, and a Color Overlay was added to brighten them up even more. I used the same Inner Shadow technique as on the closer mountains to add a bit more of the setting sun's glow peeking over the top. I told you I used this trick a lot.

To get some more glow happening, add a bright, reddish-orange radian gradient on a new layer. Change the Blend mode to Screen and lower the Opacity until you like it. This layer, like the others, gets clipped down so that it uses the mountains layer as a clipping mask. Do the same thing for the foreground mountains. At this point, if the far mountains near the right edge of the image look too bright, add a dark linear gradient on a new layer, also clipped with the rest. Usually, I would change this layer to Multiply mode, but that was a bit too dark and I was wanting to obscure detail, not enhance it, so I just used Normal mode.

Just for fun, I painted in a hint of some sort of structures at the peak of one of the mountains. There was no other reason than to try and make the background look interesting. The flat ground looks a little dull, but we'll take care of that later. On top of all these layers, make a new layer with some dark orange linear gradients on each side of the image. Change this layer's Blend mode to Multiply and lower as desired. The sun's glow stands out even more and the look simulates a camera lens vignette. Now the scene is ready for the spaceship to come.