We are neck-deep in slush. For every issue we get hundreds of submissions. Thus, I have some tips for authors...
Your story opening is crucial. I can't emphasize this enough. With hundreds of stories to read, if your opening isn't very good, editors may stop reading.
As an author myself, I know this is hard to internalize. I have written stories that I thought were really good and seen editors say, "The first paragraph was boring." And I thought, "But the next paragraph is awesome!" Too late. The editor has already rejected it.
A common issue I see is starting the story on the page before the story really begins. As an example, about a third of the stories I read the other day began with the protagonist waking up. Seriously. This is not a strong opening. I didn't hold any of these stories for voting. Another common issue is significant spelling, word choice, and/or grammar problems. These kinds of stories are more work for our editors, so more likely to get rejected.
Thus, please review your first page one more time before you send in your story. We want your story to shine. Good luck!