This article reports on an international mixed-method study on student leadership that sought to maximize opportunities for students to be engaged as researchers. Applying the conceptual lens of student voice, we reflect on students' contributions to each stage of the research. This included efforts to integrate the components of Mitra's 'pyramid of student' voice -- listening, collaboration, and leadership -- into the research design, data collection, and analysis. We worked with 'research ambassador' teams consisting of two students and one teacher at 12 schools in Australia, Argentina, China, Chile, India (two schools), New Zealand, South Africa, South Korea, Switzerland, Tanzania, and the United States. The students enhanced the research quality by playing an integral role in an online survey (n = 8,455) and interviews (n = 114) with students and teachers worldwide. The successes involved illuminating student perspectives, gathering contextual knowledge, and (potentially) overcoming power disparities. The pitfalls were a steep learning curve, navigating cross-cultural differences, and persistent power disparities. Our recommendations centred on maintaining a balance between adult researchers sharing foundational knowledge and fostering student voice. To conclude, we discuss the role of student-adult research partnerships and student representation in furthering student voice, as well as how other school stakeholders could contribute to research.