Different Sorts of Detention
I know that detention assignments vary with each teacher, but would would some of the detentions be? Let's stray away from the obvious "Write lines for Umbridge" and "Disect toads for Snape" and instead to some detentions that could be given.
i.e. In my story, my character has given Zabini and Malfoy detention and under her supervision, they have to alphabetize(sp?) books in the Historical Herbology Handbooks section of the library for Madam Pince.
I am planning on having more detentions given in my story, so some unique ones would be good.