Written by Wojciech Ogrodowczyk who takes photos, climbs mountains, and runs Brains & Beards to help companies deliver better mobile applications faster.
"How to Teach Yourself Anything, Learn More in Less Time, and Direct Your Own Education". Simple introduction to basics and tactics of learning things on your own.
A book on negotiation tactics that doesn't try to make the other side say "yes", but rather get them to commit.
It's a world-famous book on how to keep your house / office / garage (/ life?) tidy. Instead of focusing on organising techniques it focuses on letting go of stuff that we own, but do not need (in other words: clutter).
Essentialism is a how-to book for deciding what's important and what's not. It tells us how to focus on the former and get it done. As a person who likes to improve my personal (and work) processes, I obviously enjoyed it, but I also think it helped me level-up my personal productivity.