Marie Kondo attends 'Time' 100 Gala, Time's 100 Most Influential People in the World, at Frederick P. Rose Hall, Jazz at Lincoln Center on April 21, 2015, in New York City. Credit: Gary Gershoff/WireImage

On Lucy Liu's and Kate Hudson’s bookshelves: The Life-Changing Magic of Tidying Up ($10.19, amazon.com) by Japanese home-organizing guru and bestselling author Marie Kondo. “This takes spring cleaning to a whole new level,” Hudson, 36, Instagrammed, adding that the “process is liberating!” The KonMari method all comes down to two rules: declutter by category and only keep things that make you happy — or in Kondo’s words, spark joy.  "If it does, keep it," Kondo instructs. "If not, dispose of it." The world-renowned minimalism expert — whose NHK World television special Tidy Up With KonMari! airs in May — gives Us Weekly tips on how to Kondo your kids’ rooms:

Start Them Young “When a child is around the age of 3, you can teach them to start folding clothes properly,” the author of Spark Joy ($11.49, amazon.com) tells Us. “This will teach them to cherish and value their belongings.” For learning purposes, Kondo suggests choosing pieces that are easy for tiny hands to master, such as socks or a handkerchief. 

Tackle the Clothes First Kondo recommends purging belongings in the following order: clothes, books, paper, miscellaneous and then items with sentimental value. “With a child, the concept of sparking joy might be too difficult,” says the pro. Instead, ask “Which piece of clothing is your favorite?

Store Toys in One Space  Don’t worry if your little one has trouble letting go of that board game with missing pieces. “It’s OK for kids to have a time where they want to live amongst all their possessions,” says the 31-year-old mom. But it is crucial that they have a dedicated space for toys. “That is the No. 1 rule,” stresses Kondo. “It will help with the organization of the rest of your house.”

Parents: It’s OK to Toss Artwork “Things kids have made fall under the category of sentimental items,” says Kondo. “Hold each and every item and really ask yourself which one is best.” If you’re truly struggling, Kondo suggests snapping a picture of that watercolor before saying goodbye!