Reflective practice and inquiry are aspects of teacher professional practice that characterise teachers as learners. Reflective practice in some form is considered in contemporary education as an essential activity for teachers and teacher educators. "Inquiry as professional development" and "inquiry as research", on the other hand, are forms of reflective practice designed and intended to go beyond the personal. We explore the following three research and two inquiry approaches that teachers can use to inform their practice and contribute to our collective knowledge about teaching: the research methods of self-study, autoethnography and action research, and the inquiry approaches "teaching as inquiry", and "spiral of inquiry". Any research or inquiry approach used needs to fit purpose, language use, positioning as a researcher and writer, degree of reflexivity and the degree of public critique of the project. When the chosen approach "fits," our research work has a better chance of improving teaching, student progress and achievement, in short: being useful to others.