As you can see the actual 3D model is quite simple, but here are 3 things that help add realism to this scene:

1. Environment Lighting 💡
By far the best way to improve your render is with good lighting, and the easiest and most realistic way to do this is with an environmental sky texture (which doubles as a background in this scene). Not only will this add realistic lighting, but also reflections.

2. Roughness & Bump Textures ⛓
Another good way to add details to an otherwise simple model is by using bump and roughness maps in the materials. For example, the scratches on this model were done with a roughness texture, and the sci-fi panel details were done with bump maps.

3. Post Processing Effects 🌟
These are just extra effects applied to the image that help add some cool effects, such as the depth of field blur, glare on the light, and also a slight vignette effect (darkening on the corners of the image).

Obviously there are lots of other things you can do to add realism, and I didn't go in depth of how to use the above methods, but I hope this gives you some insight into the process! 😄