Despite the increase in federal tiered evidence initiatives that require the use of rigorous evaluation designs, such as randomized experiments, there has been limited guidance in the evaluation literature on practical strategies to implement such studies successfully. This paper provides lessons learned in executing experiments in applied settings, such as schools, juvenile justice agencies, mental health clinics, reproductive health clinics, and job centers. To promote successful study implementation, evaluators must understand study roles, select suitable partners, and employ appropriate partnership models. In this article, we describe partner types and study roles, concretely illustrate how partnerships might be structured, discuss specific strategies to assess implementation partner capacity and maintain partner engagement, and consider how an evaluator can leverage the skills and resources of study partners to improve participant recruitment, enrollment, and retention. While the lessons are drawn from our experiences conducting 10 experimental studies, some may also apply to non-experimental evaluations.