Developed over 80 years ago, ECT continues to be the most powerful and acutely effective treatment available for severe, often treatment-resistant, depression. Its use is supported by data from randomised trials and meta-analyses. However, there is still a need to develop better strategies to optimise ECT practice, by identifying both patient-level and treatment-level characteristics that predict therapeutic benefit and minimise side effects. This symposium will be informed by our on-going, or recently completed, clinical studies and trials. We will discuss whether we should focus our attention on the ‘average’ ECT treatment technique that suits the majority of our patients (i.e. “one size fits all”) or tailor the treatment to the needs of individual patients. Pascal Sienaert will discuss the available evidence to guide clinicians in personalising electrode position, dosing strategies and parameter selection, and to make individualised adjustments during the ECT course. Linda van Diermen will identify key clinical elements that predispose to beneficial treatment effects, distinguishing between primary and secondary predictors, and formulate recommendations to aid in patient-treatment matching. Esmee Verwijk will address why outcome measures at the group level do not always fit individual patients and how patients can be helped by preventing and/or treating cognitive side effects. The relatively neglected issue of optimising speed of response to ECT and the role of electrode placement and other clinical factors will be discussed by Declan McLoughlin. Together, the sessions in this symposium will help participants to apply evidence-based methods to personalising ECT practice for their patients.