A place for everything, and everything in its place. Obviously your parents thought of this rule before we did, but maybe that's just another reason why it's so important for getting rid of clutter.
Some clutter is just stuff that belongs someplace else.
Whether it's the kids' toys strewn through the house, a closet full of clothes that no one in the family wears any longer, newspapers piled in the corner, or paper stacked on the desk, these items are clutter as long as they are not in their proper place. The flip side of this rule means that if everything is in its place, you can find an item precisely when you want it. That event in and of itself can sometimes make your day. Use it or lose it. Efficiency counts, so store things accordingly.