The same rule applies year-round: Whatever you bring should be a treat for the hostess, not a last-minute crisis. Don't show up with flowers for which a vase has to be found, a surprise casserole, a plate of hors d'oeuvres, or anything else that demands a hostess's attention (a bottle of wine is fine if wrapped as a gift).

Flowers sent the next day are a lovely gesture. Otherwise, make your gift one that can be left on the hall table and opened later— something modest but beautiful and festively wrapped. If you know you have a dozen parties to attend this season, stock up. Richart chocolates come in a white box with a satin ribbon ($35, www.richart-chocolates.com). Fresh soaps ($22.50, www.fresh.com) come in a variety of scents, each with an elegant wrapping.