Twelve

I understand that contact lenses exist, but your character can't not be in specs all the time.

If you're writing TFiOS fanfiction, do something innovative. Don't write another Hazel/Augustus story after changing their names and DO NOT glorify cancer.

Someone write some Charlie Higson fanfiction please.

Do not name your book something stupid like Adopted by the.... CULLENS????!!! or Betrothed to.... Draco Malfoy????!!!! Honestly, that's just not how writing works.

As someone pointed out, there's also a lack of short people in fanfictions.