A guide to writing HP fan fiction

Alternate universes

In my story, you may have noticed that there is small references to Once Upon A Time character Emma Swan. She does not play a big aspect in my story, but does have a certain level of importance.

Unless you're writing a crackfic (Crackfic refers to stories in which completely ridiculous, unbelievable or insane things occur, often without reasonable explanation but great enjoyment) make sure that the characters you connect from different universes are feasible, otherwise the reader won't be able to connect with your story as much.

The reason why I decided to combine OUAT and Harry Potter is an easy one. I believed that it would flesh out my story more, and give more character development to my main character. Before you decide to cross realms, here is a few things I would think about.

A timeline
This will allow you to construct the order of your events and help you make sense of the narrative of your story (see earlier chapters for reference)

Your reasoning
Do you have a genuine passion for combining these two worlds together? Do you think that you could make a sufficient plot with the cross over of these two worlds?

Stereotypical combinations
The idea of combining two worlds together solely for the prospect of love is slightly overdone. Think carefully about your combination of these two worlds and why you want to incorporate them. For example, I am incorporating Greek mythology into my story to flesh out the plot, and create connections between characters.

Uniting two universes in one story is such a good idea, if you have written any stories like that please write them in the comments. I think the things you need to consider is one: does it add to your plot and two: is their a definite reason why you need to combine them. Remember, there is already so much in the Harry Potter universe! :)