“Factitious” should remind you of “Fictitious”. Both words denote “imaginary” things, although there is a subtle difference between the two.
The pronunciation of the word “Gaffe” is “Gaf’”, which should rhymes in a way (not entirely though) with the word “Cough” (pronounced as “Kawf”). Imagine yourself constantly coughing while an important event is underway. It could be pretty embarrassing, can’t it? Remember thus!