I have done this to represent the futuristic world of Detritus with it’s dark sky but building lit up so you can see them from a mile away. I used layer mask on the robot so that i can use the paint tool to remove the background surrounding the robot.

 I think the main background really works well with the rest of the image adding more will not make it look bad but only improve it without the background image looking bad. I could change the building colours to make them more blue and purple to represent the theme of the planet.

This was to represent the calm and adventurous world Rheaton is with it’s fresh water, food & majority of the planet having a  green landscape.