Normally, you just uncork it and let it pour, but with that special bottle of red wine you got from those fancy friends, you may need to decant. (White wines are generally good to go right out of the bottle.) With an older bottle (about 10 years old or more), you want to make sure that bits of grape skin and other unfiltered solids that accumulate in the bottle over time stay there, rather than ending up in your glass.

If you want to impress guests, use the sommelier's trick of holding the bottle a few inches above a candle while you pour into the decanter. The light from the candle makes it easy to see when you get to the solids floating at the bottom of the bottle. That's when you stop pouring. "You may give up 10 percent of the bottle to have 90 percent of it clean," says David Feldstein of Atherton Wine Imports, in Atherton, California. The wine should be good to drink right away.

When decanting a younger wine, though, let it breathe at a comfortable room temperature for about 30 minutes so it can become fuller, fruitier, and more balanced.