I still find myself writing what are essentially introductory posts to the various facets of writing. In this case, the matter of choosing a story's setting. I believe firmly that two rules here should be followed with absolute rigidity. Your story should either be set somewhere that you, the writer, are very familiar with, or it should be set somewhere that no one is familiar with.
One of the benefits of writing science fiction or fantasy is that the environment in which the story takes place can be of any nature, and no one can argue the rules or the 'truth' of that environment. The downside is that you're forced as a writer to create a completely alien universe where none of your readers can bring with them personal experience - and that is a lot of work. Most writers of sci fi or fantasy lighten the load by augmenting fantasy with elements of the real world. Here they immediately discover they are backed against the wall by the other truth. People may not know the planet Mars, and you may be able to set a mining camp there. But people do know mining camps and they do know miners ... so you had better know them too, or your story will be dead by the third page.
The setting is any frame in which the story takes place. It is critical for placing your reader into the story. The setting must be believable. It must feel 'real.' Characters play best when they are allowed to exist in situations where they belong. The place they live. The place they work. The social structure that most fits themselves. It may seem creative and imaginative to dump a mess of characters into an environment where they don't belong, but it is also a very, very overdone trope. Interloper A travels to Setting B and spends novel/film/play interacting with the setting as an interloper. Thing writes itself ... unfortunately. The story line taps into human feelings of discomfort when being pushed into strange environments, and the reader or viewer reacts with visceral understanding. And that is why as a theme it has been done to death.
Setting makes an excellent background for your story, and it can contribute in a thousand ways to the plot, the motivation or the impetus of your theme or your characters. However, setting makes a very poor character, or what is called a foil ... that is, a contrasting element in your story that enables your character to 'be' the character, revealing those things that as a writer you are writing the story to say. Setting as foil is transparent, it's dull, and it makes an easily forgettable story. When I say 'transparent,' I mean that the reader will very clearly see you, the puppet master, pulling the strings.
I am sorry, I am remiss in making this point clearly. I need to say that of course, your story CAN follow this trope. As a theme, it is sometimes described as 'man vs. nature,' though in truth that is a more complex structure than what would normally be employed, i.e., man is lost in an unfamiliar country. The gentle writer needs to know, however, that it is one hell of a steep hill to climb up in making your story a) interesting; b) innovative and c) remotely original. If I am to see or read another story about a man trapped on a desert island, it better have truly unique elements in it that challenge my previous experiences with stories of this type. The same is true for prison stories, alien planet stories, tourist in the third world stories and so on and so forth. Then again, you might be the person to write those unique elements - because you have been to prison, or you have been trapped on a desert island, or you have been to an alien planet.
If you haven't, however, and you think that writing yourself into an environment with which you have no experience would make a good story, stop. What is most interesting is that the writer must be, far more than the character, completely at home and unbelievably familiar with the alien environment in order to pull it off.
Have I gotten the whole point across yet? All right, one more try:
If you're thinking about writing a story like the one above, don't. Unless, of course, you really want to.