Mobile augmented reality games (MARGs) can be leveraged for educational purposes, as there are several examples in the literature revealing their educational value. The supporting technologies for MARGs' implementation in education are increasingly pervasive and popular, so it is time for their adoption in teacher practices. However, the integration of new practices in schools, with an impact on students' learning, requires teacher training. For that, a 50 h workshop was con-ducted to promote the collaborative development of MARGs for science, technology, engineering, and mathematics learning, which was attended by 16 in-service teachers, in Portugal. The aim of this study is to propose a set of guidelines for teacher training on MARGs, emergent from the perspectives of teachers who participated in the workshop. This is a descriptive qualitative study focusing on documental analysis of the individual final reflections of the participating teachers. The results showed that the workshop answered teachers' personal and professional needs, with an impact on their practices, in what concerns the integration of mobile and AR technology, and of games. Producing a new game during training and making it freely available for others to use seemed to be very satisfactory for teachers, and a good practice to follow. From teachers' reflections, it was possible to propose a set of guidelines useful for international readership, both researchers and teacher trainers, who aim to conceive and develop continuous professional development initiatives for MARGs' integration in teacher practices.