Be Prepared to Walk

No matter what you're buying, don't become emotionally attached to it. If you don't like the deal, threaten to leave the store. Retailers really need your business now. To gain an edge, says negotiating expert Cohen, never take a salesman's business card.

Instead, give him one of yours. If he works on commission, he'll need a transaction at some point to reach his sales target. When that happens, he'll call you.