To put the FAIR principles into practice research projects need to make choices, assisted by the professional support staff in their organisations. Research performing organisations (RPOs) therefore need to offer a supportive environment for selecting data, services, and repositories. Consider these choices from the investigators��� point of view. As a researcher, how should my project decide which data, of all that it produces, it should focus effort to make FAIR? Of all the services available, how do we identify some that will help manage data in a FAIR way? And which of the multitude of repositories we could potentially use to safeguard the data at the end of the project should we choose to do that? This guide aims to help organisations assess the support they offer researchers, data stewards and others whose role involves making such choices.