Psychotherapists need to perform tasks such as being empathetic, performing an ongoing assessment of cases, self-disclosing, making explicit treatment contracts, validating patients’ experiences and promoting awareness of psychological experience, if they are to be effective in treating personality disorder (PD). Successful therapy also requires a systematic accurate PD model. We suggest here that it is still unclear how, when and according to what session markers therapists need to perform specific operations to maximize therapeutic gains. This article describes and operationalizes a step-by-step procedure for organizing and delivering the interventions necessary for effective outcomes, such as maintaining a good therapeutic relationship, increasing understanding of mental states, reducing symptoms and improving social adaptation. The procedure is illustrated by reference to the treatment of cases of emotionally overly-constricted PDs. We include a theoretical proposal to facilitate the development of measures for evaluating the efficacy of therapist actions.