This resource, developed by members of the Global Executive Function Initiative (GEFI), presents a collection of best practices for selecting, adapting, and administering executive function (EF) tasks, and for processing, assessing, reporting, and interpreting the data generated by these tasks. We hope this resource will support researchers in conducting more psychometrically rigorous and ecologically valid assessments of children’s EFs, thereby advancing the scientific understanding of these skills across cultures and contexts.