Responding to student writing is one of the most challenging aspects of the writing instructor's job, and it is certainly the most time-consuming. Preparing future teachers to respond to L2 writing thus becomes an important aspect of any pre-service training course. In this paper, the author describes her own approach to training writing instructors in an MA TESOL seminar, using the "approach/response/follow-up" outline found in Ferris and Hedgock [Ferris, D. R., & Hedgcock, J. S. (2005). Teaching ESL composition: Purpose, process and practice (2nd ed.). Mahwah, NJ: Lawrence Erlbaum Associates]. Additional sections describe special considerations for language-based feedback and ideas for working with in-service writing instructors.