I definitely tend to try and avoid ever using pure black or white in my own backgrounds that I do, especially avoiding black lines. This ensures that when I place a black-line character on top they are assured to always stand out. The majority of these images were done in Flash, which I tend to default to simply because of how easy it is to integrate with the actual animations, and that I quite like the style besides!
Sci Fi and science-y locations I tend to be drawn to especially, as it's a great opportunity to just make things up and really push the styles.
This one was an attempt at Kamino from Star Wars: Episode II.
But it can be just as great to try and put an interesting stylized spin on realistic sorts of places that we see from day to day.