From Wabi-Sabi: For Artists, Designers, Poets & Philosophers (1994), by Leonard Koren.

Wabi-sabi means treading lightly on the planet and knowing how to appreciate whatever is encountered, no matter how trifling, whenever it is encountered. “Material poverty, spiritual richness” are wabi-sabi bywords. In other words, wabi-sabi tells us to stop our preoccupation with success–wealth, status, power, and luxury–and enjoy the unencumbered life.

Obviously, leading the simple wabi-sabi life requires some effort and will and also some tough decisions. Wabi-sabi acknowledges that just as it is important to know when to make choices, it is also important to know when not to make choices: to let things be. Even at the most austere level of material existence, we still live in a world of things. Wabi-sabi is exactly about the delicate balance between the pleasure we get from things and the pleasure we get from freedom from things.