You really shouldn’t try to build an image without having worked out your entire battle strategy for the composition, lighting scheme, color scheme, etc (advanced artists can get away with it only because they know the foundational stuff so well that they don’t need to plan ahead, but you’re not an advanced artist yet). If you try to shoehorn a background into an image after the fact, it often will look exactly like an after thought. Start your image with small thumbnail sketches, working out the composition, then rough out the general lighting/tonal composition, color palette, and when you have worked out your problems, you can proceed with the final execution.
You might want to read the sticky threads in the Art Techniques & Theories forum (linked below in my signature), to learn about the critical foundations of visual art, and the best way to plan/execute paintings.