Urgently needed innovation in twin transitions will bring about transformations that significantly impact people's everyday lives. These transitions must be science-based and sensitive to actual societal needs to ensure they realize their full socio-environmental benefits. Implementing an approach that is focused on collaborative knowledge valorisation (CKV) and supports collaboration across the quadruple helix (QH) has a powerful potential of moving such innovations beyond the current state of affairs and achieving much more sustainable and better rooted impact. Nature-Based Solutions (NBS) have emerged as a promising field where participatory planning and co-design have been experimented with recently, resulting in innovative best practices. These approaches have provided essential experience in uniting local residents, businesses, academia, and decision-makers to enhance green and blue infrastructures in a participatory and inclusive manner. A lack of knowledge, resources, and skills often hinders the maintenance of NBS, affecting ecosystem integrity and the provision of ecosystem services essential for climate change adaptation and mitigation. GreenEsteem builds on and advances best practices in the field of NBS through piloting the co-evaluation and co-design of sustainable NBS in two living labs (Konin & Sofia). Based on pilot outcomes and with strong support of expert groups and national expert roundtables, a comprehensive training program for CKV are established to tackle barriers and skill gaps among QH stakeholders. Strategic roadmaps and events launch and intensify cross-fertilization networks engaged in the green transition. Supported by an online platform featuring best practice toolkits, online training modules, a digital handbook, and policy recommendations, GreenEsteem is designed to reach practitioners, citizens and researchers alike, ensuring the replication of best practices of collaborative knowledge valorisation across Europe.