The reliable assessment of formal thought disorder (FTD), a collection of observable signs of suspected problems in generating organised thoughts, is the cornerstone of interviewing a person with psychosis. A significant gap persists between the success of assessments reported in published FTD rating scales and the practical constraints of a clinical interview. Validated rating scales largely focus on operationalised criteria for describing items; the procedural aspects of how to elicit these signs often remain implicit. We synthesise the principles and procedures of FTD assessment embedded in rating scales, translating their design into a framework for routine clinical use. Systematic employment of several manoeuvres can help elicit FTD signs: conversational stimulation, cognitive loading, social modulation and pointed clarifications to stress-test thought, language and communication processes. By making these procedures explicit, we aim to equip clinicians and trainees with a strategic, measurement theory-informed approach to the psychiatric interview when assessing for FTD.