Cultivating students' scientific knowledge and developing their capability in scientific inquiry depends on a teacher's ability to use existing resources to design rich learning opportunities. Designing such experiences is not easy, and is particularly challenging for new teachers who have little experience making decisions about the best way to develop specific knowledge and practices. In addition, a limited amount of guidance to support teachers in the practical aspects of combining the three dimensions currently exists in K-12 science instruction. More resources and preparation are needed to support teachers in using the three dimensions effectively in teaching science. A special issue of The Science Teacher in September 2013 focused on the theme "Developing and Using Models," and other supportive guides have also been released. However, engaging students in developing and using models in science classrooms is still difficult given how modeling has only recently been emphasized in science classrooms as an important practice for knowledge development. Given this, this article provides four questions that can be used to guide the use of models in teaching science: (1) What is the purpose of a model; (2) How can a model be developed; (3) How can models be used in teaching science; and (4) What should be considered when teaching with models? Each of these is considered along with relevant examples from high school students' modeling activities.