First tip here is plain and simple: When it comes to submission guidelines, do what they tell you to do. If their demands seem excessive and they’re charging you for the privilege of entry, don’t enter.
If their demands are excessive and they seem like a good outfit, take your time and make sure you do it all right.
This view is my own.
I tend to avoid any general fiction appeal with a submission guideline that stipulates “No pornography, erotica, gratuitous violence, children’s literature, profanity, sci fi…”
Not because all of my fiction contains this stuff, but because there are degrees.
Does magic realism constitute science fiction? Does a child calling somebody a pooperhead constitute profanity? Does a woman getting beaten for calling her boyfriend a pooperhead – by her boyfriend – constitute gratuitous violence?
It’s a straw-man argument, but these people have set themselves up as straw men.
If they say “No gratuitous violence” it is surely and purely a matter of taste as to what that is. But if a free-to-enter story contest theme is The Longest Journey and you have a story that fits, and the organisers say no erotica and there is no erotica in your story, send it in!
When filling in the form for a short story contest, if there’s a space for “Title” and a space for “Name of Story”, you should put Mr or Ms, etc in the Title field, rather than, like, “The First Will Toward Good vs Entropy”, or whatever you call your OWN story.
(That’s just an example name of a story.)
The reason for this is that if you put the title of the story in the Title field instead of the Name of Story field, you run the risk of receiving correspondence from the contest organisers that reads something like
The First Will Toward Good vs Entropy John Smith (instead of Mr John Smith).
Well, folks, don’t they always tell you to end on a joke? I’m outta here!