A Summary of the Cognitive Theory of Multimedia Learning
This is an excellent summation of the cognitive theory of multimedia learning and the subsequent design theories that you can apply to video creation. It provides you with a good theoretical framework. I would encourage you to focus on the 11 instructional methods presented by Mayer.
This review summarizes our progress over the past 30 years in understanding how to help people learn in technology‐rich environments and suggests some productive paths for future research. In particular, I provide a brief history of developments in creating a research‐based theory of how people learn with media (i.e., science of learning), how to help people learn with media (i.e., science of instruction), and how to determine what people have learned with media (i.e., science of assessment).