An Autoethnographic Self‐Practice and Self‐Reflection ( <scp>SP</scp> / <scp>SR</scp> ) Case Study in Acceptance and Commitment Therapy ( <scp>ACT</scp> ): Integrating Values, Culture, and Mindfulness in Therapist Development

ABSTRACT Background Self‐Practice/Self‐Reflection (SP/SR) has increasingly been recognised as a means of fostering therapists' personal and professional development. However, little is known about how mindfulness‐based SP/SR may support the cultivation of psychological flexibility (PF)—the capacity to remain open, present and engaged with difficult internal experiences while pursuing valued action—within therapeutic practice. Method This single‐case autoethnographic study explored the author's experience of engaging in mindfulness‐based SP/SR informed by principles of Acceptance and Commitment Therapy (ACT). The SP/SR process was conducted over 6 months using an ACT SP/SR workbook as a structured framework, supplemented by mindfulness notes, supervision reflections, and pre‐ and post‐AAQ‐II reflective entries. Reflexive thematic analysis was conducted on these materials, with the AAQ‐II used as a structured prompt for experiential and reflexive inquiry rather than as an outcome measure of psychological change. The analytic process followed a values‐based reporting framework, with co‐authors' feedback used to enhance reflexive rigour. Results Three themes were generated: (1) integrating personal values into therapeutic intentions, (2) recognising cultural and relational influences on identity and (3) expanding mindfulness as an embodied stance within clinical and personal contexts. Reflections on the AAQ‐II material suggested subtle shifts in PF, which were interpreted qualitatively rather than as evidence of measurable change. These findings are idiographic and illustrate one possible trajectory of SP/SR, offering insight rather than claims of transferability. Conclusions The findings suggest that mindfulness‐based SP/SR may support therapists' self‐awareness, relational understanding and professional grounding. Practical implications include attending to culturally informed values within ACT‐based reflection, incorporating compassion‐ and mindfulness‐informed exercises into therapist development, and embedding SP/SR within supervision to foster authenticity and therapeutic presence. Future research involving diverse samples and multi‐participant SP/SR designs may further clarify how personal practice influences therapist competencies across cultural contexts.