Visualisation skills in engineering education encompass the ability to construct, interpret, and mentally manipulate ideas using drawings, diagrams, digital resources, and other visual media. These skills are anchored in the cognitive capacity known as spatial ability, which, while demonstrably trainable, hinges not only on curricular design but also on learners’ cognitive flexibility. In this upcoming book chapter, soon to be published as part of the SEFI Handbook on Transferable Competencies and Skills in Engineering Education, visualisation is examined from two perspectives: spatial ability as the foundational cognitive skillset, and representational literacy as the means by which individuals externalise and communicate their thinking through visual media. It explores the underlying cognitive processes and connections to creativity, flexibility, conceptual understanding, mental models, and affective dispositions such as perfectionism. Drawing on research and practical case studies, the chapter presents evidence-based strategies for embedding visualisation skills into engineering courses, including concept mapping, digital tools, and targeted spatial ability training, and offers practical recommendations to help educators cultivate these essential, transferable skills for modern engineering practice in light of cognitive rigidity and perfectionism .