Future Landscapes: Photoshop development

I want to develop my Photoshop skills  further as it’s a useful tool for the Production Designer when producing concept art. I am trained in the more traditional approaches to design such as hand drawn concepts/costume etc. and on Carcass I had a go at drawing concepts and altering them in Photoshop. This time  I have developed images that are made up entirely of photographs. Here is one of my attempts with a few variations on colour, showing some of the stages of adaption.

The sky, moon/planet and city were all different photographs pieced together to create a composite image.

A cloud scene that is altered in Photoshop using hues/saturation and gradients. Below, the moon is added in stage 2.

Below:- Colour variation. I like to save variations just in case they come in useful for another scene at a later stage.

The addition of the cityscape. Original photo above.

…and colour variations below.