Creating backgrounds is easy. Scaling is simple stuff. just make sure if you scale big you divide it. It's like with anything in the background. If you use mbu and don't like the result, you can always modify it. The only thing is..."pretty" is opinion, not fact, and something should never discounted due to opinion. In the end, when we build a mission, we make it pretty, to our standards, and everyone playing it gets to deal with what we think is pretty. Case in point.....i love this shot....and it is "in mission" i am sure that aldo remembers it.
It is vanilla fs2, from "the time before SCP". It is also low res, on a low end machine. But that is an easy example of what you can do with scaling and orientation.