The work of the people who make datasets is crucial. They build the architectures of ground truth that shape AI systems. Yet there has been very little research that has focused on dataset creators or listened to what they have to say. In this project, we speak with 18 different dataset creators in a series of interviews that reveal the messy and contingent realities of dataset preparation. We hear about their practices and the shared challenges they face. We offer a set of actionable recommendations that would improve the practice of dataset creation while also building a more responsible AI ecosystem.