Clinical guidelines are evidence-based clinician decision-support tools that improve health outcomes, reduce patient harm, and decrease healthcare costs, but are often underused in emergency departments (EDs). This article describes a replicable, evidence-based design-thinking approach to developing best practices for guideline design that improves clinical satisfaction and usage. We used a 5-step process to enhance guideline usability in our ED. First, we conducted end-user interviews to identify barriers to guideline usage. Second, we reviewed the literature to identify key principles in guideline design. Third, we applied our findings to create a standardized guideline format, incorporating rapid cycle learning and iterative improvements. Fourth, we ensured the clinical validity of our updated guidelines by using a rigorous process for peer review. Lastly, we evaluated the impact of our guideline conversion process by tracking clinical guidelines access per day from October 2020 to January 2022. Our end-user interviews and review of the design literature revealed several barriers to guideline use, including lack of readability, design inconsistencies, and guideline complexity. Although our previous clinical guideline system averaged 0.13 users per day, >43 users per day accessed the clinical guidelines on our new digital platform in January 2022, representing an increase in access and use exceeding 33,000%. Our replicable process using open-access resources increased clinician access to and satisfaction with clinical guidelines in our ED. Design-thinking and use of low-cost technology can significantly improve clinical guideline visibility and has the potential to increase guideline use.