My students in Shakespeare learn a lot about sonnets before we tackle plays, and some of them LOVE the structure of the form. For our "Much Ado About Nothing" final project, I ask them to compose a total of eight (8) sonnets about the characters and plot events from the Shakespearean comedy.
While this sounds like a lot, I have lots of students try it. (Students in my class only need to do ONE project, and we read FIVE plays, so only interested students tackle it). Also, the extra credit works for my classroom but may not for yours - feel free to modify the whole document to best fit your needs.