Author has written 14 stories for Bible, Harry Potter, Artemis Fowl, Discworld, Good Omens, and Batman Begins/Dark Knight.
"Remember: It's wrong to ever split an infinitive and prepositions are not things to end sentences with."
There are lots of things to like about a piece of writing, fanfiction or otherwise. I personally have a weakness for idiosyncratic writing styles and crossovers. In that respect, I suppose I like ideas that I haven't encountered before.
I was once told that a good piece of short fiction asks a question. The question doesn’t have to be particularly profound, nor does the story have to provide any sort of answer—it just needs to ask something. Of course, this could just be pretentious writing-process nonsense, but it sounded good at the time.
I retain the opinion that a good story is one that has something to say, and that saying it well is just good writing.
Finally, to help contextualise anything above or below, I am a female in my very early twenties.