There is substantial interest in the possibility that cognitive skills can be improved by dedicated behavioral training. Yet despite the large amount of work being conducted in this domain, there is not an explicit and widely agreed upon consensus around the best methodological practices. This document seeks to fill this gap. We start from the perspective that there are many types of studies that are important in this domain—e.g., feasibility, mechanistic, efficacy, and effectiveness. These studies have fundamentally different goals, and, as such, the best-practice methods to meet those goals will also differ. We thus make suggestions in topics ranging from the design and implementation of control groups, to reporting of results, to dissemination and communication, taking the perspective that the best practices are not necessarily uniform across all study types. We also explicitly recognize and discuss the fact that there are methodological issues around which we currently lack the theoretical and/or empirical foundation to determine best practices (e.g., as pertains to assessing participant expectations). For these, we suggest important routes forward, including greater interdisciplinary collaboration with individuals from domains that face related concerns. Our hope is that these recommendations will greatly increase the rate at which science in this domain advances.