I am currently reading a life changing book called "7, an Experimental Mutiny Against Excess", by Jen Hatmaker that is very funny and enlightening. It is about the author's experiment to limit herself to seven things. Some of her friends tried the same concept, only with variations.
For example, the first month, she chose only seven foods to eat, the whole month, while the rest of the group chose seven countries, and ate like their poorest. The next month, clothes, she may only wear seven clothes items.
The purpose of this is to spiritually fast, while observing how our lives could be simpler, with less excess possessions. She does so in such a funny, witty fashion, which makes the book like talking to a friend.
I give this book the highest recommendation.