In our continuing discussion of feedback for authors...
Don't include gratuitious sex and/or violence. We especially don't like child rape or murder. Rape or murder of anyone is a tough sell, to be frank. Killing off characters in a short story and having the reader care is difficult. Often, there isn't enough page space to make the reader feel empathy for the victim.
That's why we prefer spooky or eerie macabre fiction rather than gory horror.
Don't offend the editors. This means, in your story, you shouldn't blatantly insult editors. Or authors. Or, anyone, for that matter. This idea holds for the cover letter as well.
Closely related to this is: don't include extreme politics or conspiracy theories in your story. I'm sorry to say, we had a story recently that included denial of the Holocaust as a major story element. Hard pass--exceptionally hard pass. In fact, we asked that author not to send us any more stories.
To end on a positive note: Do send us the story only you could write. We love personal, unique tales. What are you expert in? Passionate about? Who or what do you love? Write us a story about it!