As trait-based approaches are gaining momentum throughout the ecological, evolutionary, and ecosystem sciences, and as trait data are accumulating and becoming available for downstream use, there is an increasing need for hands-on training in trait-based research methods. Over the past decade, we have developed a series of International Plant Functional Trait Courses (PFTC) to cater to this demand. In this talk, we will be sharing some experiences and lessons learned. First, the open science movement and ‘reproducibility crisis’ also affect the plant sciences, increasing demands for reproducibility in collecting, managing, reporting, and sharing data. In the PFTC field campaigns, large teams of students and instructors collaboratively collected large and diverse trait-related datasets. Developing approaches to ensure (p)reproducibility throughout the research process has been critical to achieving training in high-quality trait data collection and management from these courses. An added value is that course data are publishable, and students can participate in the publication process. Developments based on teaching thus help meet research needs and advance researcher careers. Second, as methods for measuring and reporting traits are increasingly standardized, the field, lab, and data management approaches in trait-based ecology can be learnt independently of the specific system in which we work. This offers opportunities for international collaboration, and the PFTCs have thus far been run in China, Peru, Norway, and Svalbard, with an upcoming course in South Africa. Each course combines local research systems and expertise with a cross-course comparative aspect on trait responses along elevational gradients. General approaches combined with system-specific knowledge and need thus generate added value. Thirdly, trait-based science intersects with a broad range of disciplines, from ecophysiology via population and community ecology to ecosystem functioning. Each discipline has its own field, lab, analytical approaches, and theoretical underpinning. With functional traits as our ‘Rosetta Stone’, trait-based science is an excellent starting point for cross-disciplinary collaboration. We exploit this opportunity by having groups rooted in specific disciplines use trait-based approaches to address the overarching research question. Thus, in developing the PFTCs we have found that plant trait-based science is uniquely suited as a playground for teaching, learning, and developing research methods in an Open Science framework.