Self-regulation and metacognition are two key abilities for young musicians learning an instrument in out-of-school settings. Still, few papers present a synthesis of the ways to foster reflexive skills in this population. This scoping review aimed to identify factors conducive to these abilities according to empirical research. To be selected, studies had to involve mostly beginners or intermediate musicians, aged 16 and under; examine metacognition or self-regulation as main research outcomes; address out-of-school instrumental instruction; be of empirical design; and be written in English or French. Documentary search was carried out in French on Cairn.info and Érudit.org, and in English and French on the following databases: Academic Search; Education Source; ERIC; Music Index; PQDT; PsycINFO; RILM; and Web of Science. A total of 12 studies published between 2001 and 2024 met the inclusion criteria, of which one remains ongoing. Despite a significant lack of context diversity, several themes emerged from selected papers. Overall, studies highlighted the role of teachers and parents in supporting young musicians' reflexive skills. Furthermore, studies reported conflicting results on the links between these abilities and level of performance, and mixed findings on the effectiveness of digital tools. The presentation will also provide an extensive list of advice for helping young students to use metacognition and to better self-regulate before, during, and after every individual practice session.