Many research-based instructional materials in physics have been informed by investigations of common student difficulties – thinking that is inconsistent with canonical understandings. Our research team is beginning to develop instructional materials that elicit and build on common conceptual resources – ideas that may be continuous with formal physics. These materials are open-ended and emphasize on building from students' thinking, in contrast with other research-based materials that aim to address specific difficulties or scaffold toward well-specified conceptual understandings. We expect that resources-oriented materials like ours place different demands on instructors, and that the instructional practices that are effective in this context may differ from other research-based approaches. In this paper, we use classroom video from preliminary resource-oriented instructional materials on pulse propagation to analyze a case of resources-oriented instruction in introductory physics, to explore what knowledge, skills, and/or dispositions may support instructors in implementing this kind of instruction.