Decanters are the world's most underrated wine tool.
Cheap is OK
An expensive crystal decanter and a clean plastic pitcher are equally effective.
Slosh Young Wines Around
Exposure to air can soften the texture and intensify the aromas of young, tannic red wines (like a 2010 Bordeaux, for instance). Open the bottle and let it really glug into the decanter. Do this an hour before you drink the wine.