Try to match up your scenery with your figure's persona so everything blends in and is not out of place.
The villain here resembles a bonviveur. As a result, it seems as if he collects antiques and various outdated weapons.
Notice how I place the furniture in the foreground. This adds depth to the photo as you glance over the sofas.
Here's an example of creating layers in your photos.
Once again correspond the props to your models. The evil genius in this photo is quite modest in his tastes. His focus is on world domination not home decoration. Consequently, his office is sparcely furnished.
The scenery gives the miniatures a context as opposed to a blank sheet of white paper.
Here again the props detract from any sloppy paint work and poor basing.