The "workbook" is an underexplored concept in the literature of cognitive behavioral therapy (CBT). Unlike manuals, workbooks provide resources without prescribing standardized procedures for practitioners to follow, potentially allowing for greater flexibility. This study explored the experiences of six UK-based educational psychologists using a popular workbook, Think Good -- Feel Good (TGFG), to support CBT for young people (YP). Semistructured interviews were conducted online, and data were analyzed using thematic analysis. Five themes were identified. Practitioners felt practically and emotionally supported by TGFG. Think Good -- Feel Good was used flexibly, combined with other therapeutic modalities, and its resources were adapted. Think Good -- Feel Good helped practitioners make CBT developmentally appropriate and engaging for YP. There were potential benefits and challenges to school staff using TGFG in tandem with psychologists. Finally, supplementary resources (e.g., worksheets) helped to contain the emotional intensity of therapeutic interactions and supported practitioners to develop therapeutic alliances with YP.