Visual elements such as graphs, tables, and diagrams are essential components of scientific writing. Although scientific writing textbooks and guides often contain information on how to design such visuals, little has been written on how to effectively discuss those visuals within the text. This article offers a novel heuristic for teaching students how to effectively execute these "passages about visuals" in a way that is both conceptually simple enough to be understood by novices yet rich enough to accommodate the complexity of expert scientific writing. The heuristic consists of a set of "moves": announce, orient, observe, and explain. Following an explanation of the moves, readers are walked through a variety of examples showing the moves in context and noting the different ways the moves are arranged and executed in published scientific research articles. Pedagogical implications and approaches for using the heuristic in the classroom are then discussed.