So I am guilty of exactly ONE piece of Harry Potter fanfiction from several years ago (not including the online Hogwarts forum roleplay game that I ran for a short amount of time), and I will say that I worked very hard on the Sorting Hat rhyme for the beginning of the story. Hope you like it.
Welcome to Hogwarts,
First years of all.
We welcome all,
Witches tall and small.
Wizards bold or quiet as mice.
You’ll learn your lessons here
In a quick trice.
Now I am brought here
To Sort you, you see,
Into Gryffindor, Hufflepuff,
Or Ravenclaw tree.
Or perhaps into Slytherin,
Sly as a snake.
Here’s hoping that you all
Will very well take
To the House you belong in,
Made so long ago
By witches and wizards
Of the very best, you know.
Gryffindor, brave and strong
As a beast.
Ravenclaw’s intelligence when
All else has ceased.
Hufflepuffs work away to
Achieve the best marks.
Slytherins plot and plan.
In them, resourcefulness is art.
So step forward now
No need to be shy.
I am the Sorting Hat!
You’ll go where
Say I.

The Sorting Hat by liquidscissors on Deviantart.com