Here I show a little bit of the process for this illustration.
As a starting point, I made the sketch in the traditional way on bond paper and with graphite pencil.
I photographed the sketch and opened the image in Photoshop and proceeded to extract the lines from the sketch to resize parts of it with the free transform tool, then I changed the color of the lines to make it easier to make the tracing for the LineArt.
To make the LineArt, apply the colors and shadows I used custom brushes to give a rustic or analog touch to this illustration.
Then I added a background with green tones to look for ideas to make the background of the illustration and then I was drawing the tank and the broken tv.
The ground was made by painting and testing with various brush blending modes and colors, the sky was made by tracing colors with the brush.
Then I desaturated the sky until I obtained the desired tone.
Then I decided to add a skull on the ground and ended up drawing a pile of skulls .
To finish I added some more shadows and reflections.