A concept from chapter 8 that I found very useful was the use of "all" in arguments. There is a direct way of reasoning with "all" that will lead to a valid argument, and there is a way of arguing backwards with "all" that will typically lead to a weak argument.
The direct way of reasoning with "all" follows this structure:
All B are C
T is B
So T is C
An example of this would be:
All babies wear diapers.
Tom is a baby.
So Tom wears diapers.
This leads to a valid argument.
Arguing backwards with "all" leads to generally weak arguments like this:
All babies wear diapers.
Tom wears diapers.
So Tom is a baby.
This is a weak argument because not every single person that wears a diaper is a baby. This argument is weak because it disregards many other possibilities and therefore it is not a dependable argument.