Writing and communication are essential skills for success in the workplace or in graduate school, yet writing and communication are often the last thing that instructors think about incorporating into a mathematics course. A mathematical modeling course provides a natural environment for writing assignments. This article is an analysis of the type of writing assigned in my mathematical modeling course. Where the assignments are unusual, they are thoroughly described and I share my experiences on what worked well and what was not as successful. Where the assignments are more traditional, I offer an analysis of problems and pitfalls in teaching writing. Formal project reports for the class teach students how to write scientific articles. Unusual reflective assignments help students integrate their learning and apply it in new contexts.