10 steps to becoming a hoarder

1. Early in your married life, take organizational tips from your mother-in-law (RIP), such as "pile stuff in laundry baskets to deal with it later."
2. Start a scrapbooking habit, take zillions of pictures, then fall desperately behind in scrapbooking for, say, 7 years. Put all the unscrapped photos into laundry baskets. Pile scrapbooking tools into a corner nearby.
3. Move on to stamping and create a smaller, though similar collection of rubber stamps, inks, paper.
4. Inspect bags your husband is hauling up from the toy room to take to Goodwill. Remove 40% of what he attempted to giveaway. You're saving the toys for the grandchildren (who might be born in 15 years or so).
5. Don't have the heart to decline anything offered to you by your husband's 92-year-old grandmother, even if you really don't need a battery-operated talking parrot, 3 Clinique giveaway bags or a yellowed U.S. map mounted on plywood. You don't want to hurt the woman's feelings. 
6. Marry a man who cannot part with anything that has to do with Star Trek or Star Wars.
7. Ask your children "do you want this?" before you throw anything away. 
8. Be sentimental enough to want to keep a newborn-size diaper (unused, of course), the hospital wristband your daughter wore when she had her tonsils removed, and the first letter your son wrote to Santa, plus about 17,000 other small pieces of their childhoods.
9. Maintain enough optimism to truly believe that you will fit into those clothes or they will come back into style someday.
10. When you finally decide to get rid of stuff, waffle back and forth between giving it away, throwing it away, saving it for someone else you know who might want it, or trying to sell it on Ebay. Put stuff in laundry baskets until you can make up your mind.