Guilty Until Proven Innocent
Thumb rules are life savers. Instead of muddling with theories, they give you practical solutions. If you find a useful thumb rule, you better write it down. Like catching a rare pokemon as soon as you see it.
Here's a thumb rule I found for living a minimalist life: Guilty Until Proven Innocent.
Have a look at all the objects in your room. They are all guilty of uselessness until you can prove their use. Pick one object and think of why it exists in your room. Can't come up with a convincing use? Throw it in the dustbin or give it to the needy.
Repeat until your room is clean.