This white paper develops a reference workflow for the discovery, access, processing, analysis, publication and reuse of research data, drawing on the Integrated Carbon Observation System (ICOS) as a mature example of an end-to-end data infrastructure and complementing it with relevant practices from NFDI4Earth. The ICOS case demonstrates how distributed data generation can be connected through standardised processing, quality assurance, metadata, persistent identification, publication services and long-term preservation. These elements provide a useful reference for designing interoperable and reproducible data workflows that extend from the initial research question to the reuse of derived data products. Based on the ICOS case, the white paper proposes a generic workflow comprising the stages Define, Find, Assess, Access, Process & Harmonise, Analyse, Publish, Preserve & Reuse. The workflow is deliberately non-linear: researchers may enter at different stages and move back to earlier steps when data quality, methodological requirements or emerging research questions require additional data or alternative resources. The resulting recommendations highlight the importance of connecting data discovery with assessment, access, processing and provenance, while providing machine-accessible interfaces, interoperable metadata, reproducible computational environments and mechanisms for publication and long-term preservation. The workflow is intended as a transferable reference model for improving the integration and reuse of heterogeneous data resources across NFDI4Earth and, in particular, for strengthening the connection between governmental data infrastructures and research workflows.