Proofread, check spelling, punctuation, and grammar.
Over half of the manuscripts I receive have neither a title, byline, nor contact information. If the manuscript is separated from the pitch email, I can’t publish the piece, no matter how good it might be. That story will end up in the closed file.
Read your draft aloud before submitting. This will help you catch odd sentence structure and silly typos that you missed by proofreading with just your internal voice.
Names that identify the subject and the author or photographer make an editor smile.
Spaces, you know, the thing that occurs when you hit the space bar on your keyboard. They are an essential part of written language. However, those spaces, when misused, can drive an editor loopy.