A growing number of inter- and transdisciplinary (ITD) toolkits provide methods, processes, concepts, heuristics, frameworks, and other resources for designing and implementing ITD research. A brief overview of the currently fragmented toolkits landscape is provided, fleshed out through descriptions of four toolkits. Fragmentation means that researchers are unaware of, and do not have access to, the full array of tools that could benefit their investigations. Overcoming fragmentation requires attention to toolkitting, which is the relatively overlooked bundle of practices involved in the creation, use, maintenance, funding, and study of toolkits. In particular, the processes and expertise involved in the creation, maintenance, and study of toolkits are described. Toolkitting as metawork can make resources more accessible, useful, and rigorous, enhancing ITD research. Future toolkitting can be strengthened with attention to key questions that can guide the activities of, respectively, toolkit creators and curators, scholars, and funders. Examining the toolkits landscape through the lens of toolkitting suggests that the development of a comprehensive, ongoing inventory is a first step in overcoming toolkit fragmentation. An inventory could also be the foundation for an even bolder initiative—a federated knowledge bank—that connects and develops the range of existing and future toolkits. The inventory and federated knowledge bank also provide a shared project to bring together the expertise of ITD toolkit creators, curators, users, funders, and scholars to achieve a step-change in enhancing ITD research.