Let students actively explain the material to each other, then they are actively engaged with it. A meta-analysis (an analysis of numerous studies) shows that explaining the material out loud is good for learning performance. Researchers suspect that this is because students are actively engaged in retrieving the knowledge from their memory. Moreover, by taking on the role of teacher, students are motivated. As a result, students engage more actively with the material, paying more attention to details and spending more time understanding the information. So, for example, plan an activity in the lesson where students have to explain the learned material to each other.
Bowman-Perrott, L., Davis, H., Vannest, K., Williams, L., Greenwood, C., & Parker, R. (2013). Academic benefits of peer tutoring: A meta-analytic review of single-case research. School psychology review, 42(1), 39.
Cohen, P. A., Kulik, J. A., & Kulik, C. L. C. (1982). Educational outcomes of tutoring: A meta-analysis of findings. American educational research journal, 19(2), 237-248.
Galbraith, J., & Winterbottom, M. (2011). Peer‐tutoring: what’s in it for the tutor?. Educational Studies, 37(3), 321-332. https://doi.org/10.1080/03055698.2010.506330
Koh, A. W. L., Lee, S. C., & Lim, S. W. H. (2018). The learning benefits of teaching: A retrieval practice hypothesis. Applied Cognitive Psychology, 32(3), 401-410. https://doi.org/10.1002/acp.3410