Purpose: As research increasingly links positive student-teacher relationships (STRs) to positive student outcomes, instruments to measure STRs have proliferated. Yet most neglect student agency and sociocultural variation in the operationalization of STRs. This study explores the specific actions teachers and students take to build positive STRs from the vantage point of a diverse group of US middle and high school students. Research Methods: Drawing on the principles of critical collaborative research, our intergenerational team of scholars engaged 84 youth participants (ages 12-18) in qualitative data generation and analysis, using novel youth-voice elicitation techniques known as the fishbone and diamond card sort. Findings: Findings highlight specific actions that a diverse group of youth believe students and teachers take to create positive STRs and foreground the importance of teacher power, student responsibility, safe classrooms, and reciprocity in STR construction. Implications: By pinpointing specific actions that teachers can take to build positive STRs, this work raises implications for teacher education and professional development, especially as schools struggle to regain ground with students in the wake of COVID-19 disruptions. In addition, the study demonstrates how engaging youth as partners in qualitative research can help improve the conduct and products of empirical research in education, offering a model for the field of youth validation processes.