Consistency with your story is an important thing.

I am guilty of not being consistent, in my Them and Us series I didn't plan out the story, so I lost sight of what the plot was and it became something completely different!

This is why I now always plan out the endings of my books. For instance, I often write the chapters containing important events near the beginning of the writing process.

I also often write most of the book before I begin publishing it, so that of I change my mind, I can go back and change any details of I want to.

Basically what I'm saying, is make sure you know where you want to take your story. This can be applied to both fanfics and originals.

My plans normally look a bit like this:

I bullet point important things, and where they fit in to the story. Then when I am writing it I go back and highlight the things that I have written. It's a sort of brief guide of what the book will look like once it's done. I find this especially useful when writing a post book fanfic (like the Exchange, which takes place after both the HP and HOO series have ended).

Use this structure of you would like, and go forth and write!

Remember to vote, comment and be amazing!
~Em xx