Data sovereignty is paramount in the digital era, and data spaces are often viewed as a means for organizations to cultivate this essential digital competency. However, the adoption of data spaces by organizations remains limited. Furthermore, current perspectives on data spaces tend to emphasize technical aspects while overlooking their socio-technical complexity. What's lacking are recommendations for establishing federated data spaces. To bridge this gap, the study advocates the development of recommendations through expert interviews. Targeting both academia and industry, this research employs coding techniques akin to grounded theory to offer insights and propose four key categories of recommendations: Community, Infrastructure, Interoperability, and Governance. Leveraging data spaces for data sovereignty can provide organizations with a competitive edge.