Spend quality time to build that story- No story is too small for you to commit your best into. Don't under look any story even if it is just a page. Write it in a way it will entertain people and also add something to the wealth of their knowledge.
Let your short story have;
1. Clear idea- the central of your story. What the story revolves around.
2. Purpose- to inform, to educate, to inspired, to motivate...
3. Audience - the specific people you are writing to. Male, female ,children, married, single.
4. Character - well developed character.
5. Settings- Different settings- place, time, weather...
6. Theme- the center message.
7. Subject matter- who/what the story is about.
8. Point of view - Angle of narration
9. Plot- sequence of event
10. Diction- language used.
11. Tone- mood of your story.
Someone is saying all these in a short story? Yes, all these and even more. When you add all these together with good story line it gives you a quality story.
After you have written your story, edit it. Then proceed to proofread it.
Aside that this is the way it should be, a story no well written pisses of readers. Writing a good short story will surely help you to build a bigger story.