I have written some advice on how to give a talk - that is the basis for a lecture in my grad classes.
These links are old - from a 2012 class pointing to a 2011 blog posting. I think the information is timeless. I recommend starting with the 2012 thing which introduces the 2011 thing. I do need to update these. I still use those blog pages as readings in my class (2020).
My advice on how to give a talk hasn’t been converted to the format for this website yet, so have a look at http://graphics.cs.wisc.edu/WP/animation11/2011/04/08/advice-on-presentations/.
(in subsequent years I refer students to this http://graphics.cs.wisc.edu/WP/vis12/2012/04/18/reading-20-presentations/)
In the 2015 Vis class, I asked students to look at this, but there was no additional info.http://graphics.cs.wisc.edu/WP/vis15/2015/04/22/reading-23-videos/