First of all, I will try to maintain the original image's look.
Composition
Explore some basics of composition. In photography, a basic one is the rule of thirds.
This means that if you divide your frame in a 3x3 grid, some elements should be in those lines.
Look how none of your elements follow this composition rule.
If you place some elements on these lines, the image starts to look more interesting. It is regardless of any additional detail, maintaining the same style.
Planes
You probably want your image as it is, but to add more interest you can put elements of different sizes, making them appear as different planes, front, medium, back plane.
Point of interest
Add something to draw attention into. Something simple is ok, but to add context to your scene.
Besides that, you can try different styles, but that is another topic. Add gradients, textures or more detail to the images.
@Welz answer comments these points, but the truth is that those are changes in the style you have. The composition is the first thing you want to work with. Leave the details for later.