Dr. David Tolin suggests: "The question to ask yourself is not whether you can use the object, but whether you really will use the object. A good rule of thumb is that if you haven't used an object in over a year—say, you didn't even know it was there until you found it on the bottom of a pile—you probably can live without it."
2. More is not necessarily better.
"There's really no need for most of us to have, say, two microwave ovens, or three bicycles," Dr. Tolin says. "Try to get rid of the extras."
3. Categorize items into piles.
For example, you might make a pile of things to keep, a pile of things to donate to charity, a pile of things to sell or give away and a pile of things to throw away. "Don't make too many piles," Dr. Tolin says. "Having to decide among 10 piles just slows you down and strains your thought processes."
4. Don't overthink.
"If you have to go through a long and complicated decision-making process for each and every item before you get rid of it, you'll never get free of the clutter," Dr. Tolin says. "Most decisions are not that complicated. If you find that the decision takes you more than a couple of minutes for a particular object, you are probably making it too complicated."
5. Learn to get past some of the imperfections—it's okay to make mistakes.
6. Follow the "OHIO" rule: Only handle it once.
"If you pick something up, make a decision about it and then put it somewhere it belongs," Dr. Tolin says. "If you find yourself handling things again and again, moving things from one pile to another, stop yourself. Refocus and move on."