We suggest that instructors and TAs make use of our large selection of anonymized sociology writing samples to ground discussions of writing in the classroom.
You may also want to get students to volunteer to have segments of writing workshopped in class. This works best when you can see the work submitted online, select some possibilities, and privately ask a few students if they are interested. Naturally you need to make it clear that this is absolutely optional, with the purpose of helping them. (We would suggest choosing work which is "getting there" rather than poor.)