"Fluent Forever: How to Learn Any Language Fast and Never Forget it" by Gabriel Wyner: A Review
There are a huge number of books available on language learning techniques. However, I found "Fluent Forever: How to Learn Any Language Fast and Never Forget it" by Gabriel Wyner to be an excellent resource for independent language study and tailoring available resources to suit your own learning style.
In this well-written book, Wyner deconstructs the language-learning process, taking a look at what is really going on in our minds when we learn new words and phrases. With tips on effectively learning and retaining pronunciation, vocabulary and grammar, this is a great resource for professional linguists, aspiring polyglots, and those wishing to pick up some useful words and phrases for an upcoming holiday.
Wyner himself speaks six languages fluently, which he has learnt independently in the past few years using the techniques described in this book. This is a must-read for anyone looking to improve the efficiency of their language study!