What are the important aspects to consider before creating a story?
There are several things which should be considered when creating a story. Here are a few of them:

1. Who is the intended audience for the story?
2. What messages or themes are trying to be conveyed through the story?
3. In what ways can the medium the story is being told in be used to its fullest to aid the storytelling?
4. Does the story cover new ground? Or is it a re-tread of ideas that have already been done in other stories?

These are only a few ideas to help get you started. Please let me know if you would like more!
For example, I want to create a sci-fi story. Can you offer some advice about the above four points?