This New Zealand-based study of the classroom practice of nine exemplary teachers of writing to upper primary-age students explored the significance of task orientation as a component of effective teacher instruction and the instructional strategies or actions that effective teachers utilise to promote such. Effectiveness pertains to teachers being able to generate a positive impact on learners' engagement and academic outcomes. Particular attention was given to the content and organisation of the tasks and activities that teachers required of their students. Analysis of observed teacher practice in relation to learner gains showed actions associated with task orientation to be strongly associated with student progress in writing. Two indicators linked particularly with learner gains in writing. They relate to teachers being able to select and promote learning tasks that are purposeful and challenging for students and to students being involved in the selection or construction of learning tasks. There were relatively high levels of proficiency with regard to teachers being able to select and promote purposeful and challenging tasks but significant operational variability with regard to teachers involving their students in task selection or construction. Classroom illustrations are provided on how effective teachers promote learner involvement in task selection or construction.