I am going to leave a note as it took me some time to figure out why my brushes with Dyntopo enabled weren’t adding more geometry.
It is to do with the fact that if the setting is Relative Detail, it depends on the distance from the object. By switching to Constant Detail (which is now my favorite option) and setting Details = 8 or lower, all started to make sense in the video.
This concept is explained later on in the other videos but I got stuck at the beginning on this video trying to add smoothness.