I would recommend Kevin Horsley's Unlimited Memory[0] over Foer's Moonwalking with Einstein.

Foer is a lot of hype and unfocused, whereas Horsley almost immediately gets down to brass tacks after a brief introduction meant to energize you, and provides a great general overview that leaves you with the knowledge of how to continually improve beyond what the book provides.

[0] https://www.amazon.com/Unlimited-Memory-Advanced-Strategies-...

I enjoyed Moonwalking with Einstein, but I felt that it was more story than technique.

I found [Unlimited Memory](https://www.amazon.com/Unlimited-Memory-Advanced-Strategies-...) a nice follow-up to the former.