WHAT TO SAVE: Receipts for items you may want to return, big-ticket receipts for insurance, and those required for tax purposes.

HOW TO SAVE: Keep track of receipts in a resealable envelope, like the small pouch from Muji (shown here, 8 by 6 1/2 inches, $2, www.momastore.org). Go through them once a week. File credit-card receipts by company in an accordion check file, such as the Staples Poly Expanding Check File (10 by 5 1/2 inches, $4, www.staples.com), and toss unneeded cash receipts. Once a month, toss ATM and deposit slips and credit-card receipts after checking them against your statements; file the rest under Returns, Insurance, or Taxes.