EOSC strongly emphasises FAIR and interoperability, but current guidelines leave too many choices to each repository developer, which means lack of interoperability and little shared tooling. RO-Crate makes a common metadata overlay across established EOSC repositories and provides pragmatic step-by-step guidelines and software libraries for implementers. RO-Crate is a community-developed method to share Research Objects with FAIR metadata, based on Web standards and best practices. RO-Crate is now being established as a viable Linked Data realisation of FAIR Digital Objects, highlighted by the EOSC Interoperability Framework. In this talk we demonstrate how RO-Crate is used by multiple EU, US and Australian projects, across research domains from life sciences to cultural heritage. We show how RO-Crate helps researchers gather FAIR descriptions of heterogeneous resources in EOSC repositories, including computational workflows. RO-Crate gives flexibility for domain-specific extensions and re-use FAIR infrastructure in EOSC, e.g. PID services and semantic registries.