Spaceship Design: What makes sense, and what's nonsense?

[Opellulo]

As many have already pointed out you have to decide how much "Space Magic" (FTL, artifical gravity, etc...) you want to use but, even after considering this, you have to work into account an often overlook element: logistics.

"Standard" space ships makes no sense: too big to be built and launched from a planet and too resource expensive to be built in orbit. Anything that complex requires a logistic network that's going to be much more important than the space ships there produced.

So maybe a more sound approach would be to design the space infrastructure and then populate it with the necessary spacecrafts to operate it: unmanned mining drones, orbital space stations that works as switch from space travel to atmospheric descent, surface launch pad that works as heavy traffic cargo launchers, this kind of things.

An aircraft doesn't land on your backyard and for the same reason a craft able to deep space travel should not be able to land anywhere on the surface of every planet.