How Many Pens and Pencils Do We Really Need?

My 90 year-old father is preparing to leave the home he had built in 1964.  50 years' accumulation now awaits my siblings and me.  I have gotten the ball rolling until they can arrive from out-of-town.
It's a cautionary tale as I go through the remnants of my parents' lives.  It is bittersweet, to say the least.  These are the phrases that have come to mind:

"Use the hotel soaps.
Eat the nuts you bought at the Virginia Peanut Foundation (or wherever that 22 oz. vacuum packed tin came from in 1997).
Donate your extra fabric and yarn to someone who will use it.
If you buy photo albums,  fill them.  The photos don't get better with mildew and disorganization.
Use your 'good' china and crystal - often.
Cracked and chipped plates and glasses can't be restored.
Throw away empty chocolate boxes even if they're 'too pretty to throw away.'
Rubber bands don't improve with age"

And so on. 
After I'm done with Dad's house, mine will be next.  I don't want my nieces and nephews wandering through the jetsam of my belongings saying, "Why, Susan?  Why?"