This study analyses the practices of nine New Zealand teachers of upper primary and middle-school students (N = 210) whose classes had consistently shown gains in writing far greater than normative expectations. Data from observations of three writing lessons and related interviews with each teacher, plus interviews with three focus students after each lesson, were considered in relation to learner gains in writing. To analyse these data, a content analysis matrix was constructed from selected writing research literature, yielding eight dimensions of effective practice: expectations; learning goals; learning tasks; direct instruction; responding to learners; motivation and challenge; organisation and management; and self-regulation. Instructional moves associated with each were defined. There was a significant association between three dimensions (learning tasks, direct instruction and self-regulation) and learner gains. Analysis also indicated that these effective teachers of writing employed an interconnected range of instructional moves in a strategic and flexible way. Instructional actions and activities are particularly effective if regarded as purposeful by learners and if they include meaningful opportunities for learner involvement. The findings detail strategies for generating higher than anticipated gains by learners.