What does thoreau advise people to do to ensure their lives are not "frittered away by detail"?

Basically Thoreau advises everyone to live, well, simply. Inspired by all the people who have died living unfulfilled and unnecessary complicated lives, he states that people should live sincerely and do what they think is meaningful to them and their loved ones. This quote comes from the Thoreau’s acclaimed work "Walden" in which he gives his views on living simply in harmony with nature. It’s with that in mind we have to analyze this work.