A couple years ago when I was attending a year-long company-sponsored leadership curriculum, a presentation class (not just Powerpoint class) was part of it. Since then - after lots of practicing - I passed some of the learned on to my teams. The most important part of a presentation is to have the right content for the audience, have it well-structured, added with the right amount of "gimmicks" to make the content sink in faster and deeper.
Unfortunately, after many presentations you leave wondering "What is the message?" and "Could even more 'data' be packed on a single slide?". And sometimes they even fall into something like here: