To create such a fanfic, immerse yourself in the world of the book. Analyze the relationships and conflicts. Maybe start with a 'what if' scenario and build from there. Don't forget to keep the writing style engaging and the story coherent.
First, you need to have a clear idea of the message and tone of 'How to Win Friends and Alienate People'. You can then introduce new characters or settings that interact with the existing concepts. Make sure the story remains true to the core ideas of the original work while adding your own creative twists.
Well, start by really understanding the themes and characters of the original book. Then, think of unique scenarios and plotlines that could expand on those elements.