Every class has a first day, yet many professors only read the syllabus to students rather than more intentionally leveraging the day to set up understandings that enhance learning and classroom management. Logic, experience, and research indicate that it is not just content expertise that matters to student experience and learning: it is also the environment that the faculty member creates--ideally engaging students as active participants. This paper will increase awareness of the importance of planning and performing the first day, review alternative first day approaches in terms of the primary goals they satisfy--content connection, interpersonal connection, student face needs, motivation, and expectation setting--and provide a detailed outline, and rationale, for a flexible, transdisciplinary first day exercise, the Three Boards Activity, that offers benefits to both the students and faculty member and is adaptable to any size class. Handled thoughtfully, the first day can do more than convey basic information: it can also set the tone and model optimal attitudes and behavior for the classroom.