A few years ago, Sara Aiken planned the perfect romantic Christmas celebration with her husband, Ken. She made eggs Benedict, bacon and Bloody Mary cocktails for brunch. Then the couple lounged around in their pajamas and exchanged gifts.

Ms. Aiken gave her husband a foul-weather jacket for sailing, some history books, cashmere socks and a pair of cuff links. She didn’t see any packages for herself under the tree, but got excited when he handed her a Christmas card and said her gift was in it. “I remember thinking: ‘The possibilities...