I have spent the two last days at a “Train the Trainers” workshop organized by the Carpentries project. Here I will summarize some thoughts on the workshop, and things that I will take with me for my own teaching practice. The Carpentries The Carpentries project comprises the Software Carpentry, Data Carpentry, and Library Carpentry communities, with a shared mission to teach foundational computational and data science skills to researchers. I have taken several Carpentries lessons over the last years, organized by volunteers here at the University of Oslo.