[inetsee]

There is a book titled "Thinkertoys: A Handbook of Creative-Thinking Techniques". The last edition was published in 2006, so it's fairly dated by now. I found it very interesting back then, but it wouldn't have much about more recent tools or ideas.

There is a summary of the book here https://www.ethos3.com/books/thinkertoys-a-handbook-of-creat...

[chadcmulligan]

This is a good one to - "The Thinker's Toolkit: 14 Powerful Techniques for Problem Solving" by Morgan D. Jones, ( techniques as used by the CIA no less! :-) ).

https://www.amazon.com/Thinkers-Toolkit-Powerful-Techniques-...

[seesaw]

+1. I found one in my local library few months back. It breaks down the process to solve a problem and lists different approaches. It is a good read.