I am a huge fan of Nancy Duarte’s presentation philosophy, I own three of her books, and I build my presentation rubrics in my class around her guidance. Here are two quick videos to serve as a starting point to make better presentations.
This video is a nice and short, elevator pitch version of her vision, and I suggest all teachers watch it and share it with students.
You can follow this link (embedding this was a pain, so I am linking to it instead) to another video that talks more tactically about how to design better presentations. It is also from Nancy Duarte’s work, but it is made by Harvard Business Review.