In this immensely practical article, four college mathematics professors answer a call from the Conference Board of the Mathematical Sciences to bring effective active learning into post-secondary math classrooms. Though many independent school math instructors are already running student-centered classrooms and might be familiar with active learning, this article provides a comprehensive compilation of strategies as well as an explanation of the pedagogy of active learning, including the math emporium model and inquiry-based learning. Additionally the authors discuss the kinds of excellent outcomes that teachers can expect to see when they move to this type of instruction. They also anticipate concerns that teachers might have as they contemplate moving away from the lecture/homework cycle. While acknowledging the associated worries, the authors provide a reframing of what it means for students to understand content at a deep level and build skills not just in problem-solving, but also in metacognition, independence, creativity, and other important habits of mind. If this piece piques interest, the professors also have a six-part series on active learning on the American Mathematical Society blog On Teaching and Learning Mathematics.