Staring at an odd mitten, your college astronomy notebook, an elephant-foot umbrella stand? For you facing The Spring Cleaner's eternal question--"To trash or not to trash"--here are "clutter-control" rules from professional organizers:

* Hemphill's Principle: "If you don't know you have it, or if you can't find it, it is of no value to you."

* Fogelman's Dicta: "Does it have monetary or sentimental worth? When is the last time you used it?"

* Winston's Wisdom: "If the only reason you are saving something is because it 'might come in handy some day,' chances are you are hanging onto clutter. Throw it or give it away."

* The Hemphill Memorabilia Technique: Each year, give every person in the family a box for report cards, travel folders, Valentine cards and other selected mementos. Label and store box in an out-of-reach closet, to be pulled out and enjoyed on some future rainy day.

* Organizers' Favorite Proverb: "Wisdom is not the accumulation of information, it is the elimination of information."

And other laws:

* Parkinson's Law of Clutter: Junk will expand to fill the space allotted.

* Murphy's Law of Spring Cleaning: You won't need something until the day after you've thrown it away.