If you haven't used it or worn it in two years, sell it. If you hate it but are keeping it because it was a gift, sell it. (Just make sure the giver does not attend the sale.) "Try to go through your house objectively," says Leslie Kaplan, co-owner of the Boston consignment store Garage Sale. "You have a ton of stuff that may be great but you have no use for anymore." Look at your items as if you were seeing them at a garage sale. Would you buy them again, even at a discounted price? If not, then sell them, keeping these points in mind:

Best-sellers tend to include baby equipment (strollers, car seats), sporting goods, furniture, tools, books, kitchen appliances, toys, and framed art.

Clothing usually doesn't sell as well, because by the time it's for sale, it's already out of fashion. But brand-name and children's clothes are exceptions, says Jennie Callahan of Fort Payne, Alabama, who has earned up to $1,500 a weekend at The World's Longest Yardsale, a multistate event held each August. Carey Rademacher, creator of ItsDeductible, a donation-valuation software program, always donates clothing instead of trying to sell it. "A bagful of brand-name or designer clothing could be worth a $250 tax deduction versus a fraction of that at your sale — if the clothes sell at all," she says. But if you are less concerned about money than about clearing your home of clutter as quickly as possible, go ahead and bring out that pile of clothing — just keep the prices low.

Don't repel potential buyers with used cosmetics or lingerie (yes, it's been done). “Garage sales are recycling sales, not garbage dumps," says Rinker. "Don't sell broken or damaged goods. What you sell should be stuff somebody else can use that has no value to you."

Don't hawk antiques or truly valuable collectibles (which may include items that are 25 years or older). Tag-sale shoppers expect to pay very little for your unwanted goods, and there are better markets for such items. Call an appraiser, and consider using an eBay trading assistant to fetch the best prices for your stuff (see Sell Valuable Antiques and Collectibles Online).