Positive Thinking Discover the Power of Positive Thinking and Change Your Mindset to Become an Optimist Part of the (Mind Hacks) series by Hanif Raah is a good how-to book.
I received a complimentary Kindle copy in an Amazon promotion. That did not change my opinion for this review.
I gave this Positive Thinking book on how to become an optimist four stars.
"Positive thinking is the best and most powerful tool you can have to achieve happiness and success. Research studies confirm that it brings about happiness, health, success, inner peace, improved relationships and longevity. It makes your life easier, richer and more fun."
Link to purchase: https://www.amazon.com/Positive-Thinking-Affirmations-Happiness-Motivation-ebook/dp/B00UTY3V26