Selecting the most appropriate components for a blended learning course is a multifaceted challenge influenced by various criteria. The impact of these influential criteria on the design process is not always obvious. The aim of this study is to assist academics in designing sustainable and engaging blended courses by investigating the impact of these criteria on the selection of blended learning components. By selecting the right mix of components, academics can foster a sustainable and meaningful involvement of students in their learning process over time, ensuring that students’ engagement is both enduring and beneficial in achieving academic success. A modified Delphi survey was utilized in this study, involving the participation of eighteen experts experienced in instructional design and online teaching. The analysis primarily relied on quantitative methods, utilizing the mean (to indicate central tendency) and standard deviation (to measure dispersion) for presenting the experts’ responses. Additionally, qualitative analysis of experts’ comments provided deeper insights into their quantitative ratings. Findings indicate that face-to-face collaborative activities should be the preferred method of delivery for academics aiming to enhance students’ engagement and foster their higher-order thinking skills, which students often find challenging. However, this approach is most effective when the group size is manageable. For larger student groups, online collaborative work can be a suitable alternative, provided there is ample online resource support. The results also indicate that online self-paced learning can be advantageous for lower-order thinking learning outcomes, particularly in situations where teaching staff is limited.