Research on writing tasks suggests that cognitively demanding tasks are important for student learning. Though a great deal is known about high-quality writing instruction, less is known about how teachers, through their instruction, support students to complete tasks at a high level. This qualitative study examines three preservice teachers' writing instruction to understand how their instruction does--and sometimes does not--support the demands of the tasks that they provided for their students. The findings suggest that preservice teachers' instruction appears to align with expectations for good writing instruction (e.g., using models), but that they often struggle to enact these practices in a way that supports the complexity of the tasks.