Not much in your wardrobe is more basic than a soft, comfy, wash-and-wear cotton T-shirt. The only potential complication: Along with small, medium and large sizes, there are slim and regular fits. Just like the T-shirts, though, the differences are easy and basic.

The move to slimmer fitting shirts began in 2000, "Bloomberg" says, with the youth market driving the change. A regular fit T-shirt runs in a straight block, from armhole to waist. With a slim fit, the sleeves will be more fitted; chest and back measurements may be a bit smaller, and the length may even be an inch or so shorter. While the slim fit is fashionable, you might consider the regular -- traditional -- fit if you're a bigger size or if you just like a loose fit for comfort.