What the video taught me was to look at my main characters' tension arcs through the novel. Even with a not very exact representation of this (see below) I could see where the 'dead' points might be for the reader, and where there was too much going on.
The timeline runs left to right and the peaks represent crux points for that character. It took less than three minutes to do, but was nevertheless very informative. As I often work with historical characters, sometimes their peaks and troughs are determined by the history I'm dealing with. In my last novel it was real events in WWII. This can lead to imbalance in story structure which needs to be addressed, but it can be invisible unless you take a quick overview.
My four hundred page novel reduced to a few squiggly lines might seem laughable, but as Kurt Vonnegut points out, if it works for the New Testament, why not for me?!
What deceptively simple writers techniques do you use when writing?