Purpose: Stories of employability are told in employment and educational settings, notably the selection interviews. A popular training approach guiding higher education students to construct employability stories has been the past-behaviour storytelling method. However, insufficient research exists regarding the method's effectiveness and optimisation. This study examines whether the method (1) increases the quantity and quality of interview narratives in story forms and (2) can be enhanced by image stimuli. Design/methodology/approach: In a double-blind randomised control trial with repeated measures, participants submitted four weekly interview narratives. After receiving past-behaviour serious storytelling training in Week 3, they were randomly allocated to an exposure group using images and a control group using keywords as a placebo to continue producing interview narratives. The interview narratives were assessed based on the number of stories and quality ratings of narrative conformity, relevance and conciseness. Results before and after the training, and with and without the image stimuli, were analysed. Findings: Training increased the number of stories. Training and repeated practice also increased narrative quality ratings. However, the image-based intervention was the strongest predictor of improved quality ratings (effect size 2.47 points on the observed scale of 0-10, p < 0.01, 95% CI [1.46, 3.47]). Practical implications: A pre-existing ability to tell employability stories cannot be assumed. Training is necessary, and intervention is required for enhancement. Multi-sensory narrative interventions may be considered. Originality/value: This study is the first known double-blind randomised control trial with repeated measures evaluating if storytelling training and image stimuli improve interview narratives.