Few things shout fall quite like a plaid shirt. But not every plaid shirt is made of heavy wool in an oversized fit. For early fall, when the temps are still in the low 70s, opt for the slimmed down, lightweight cotton version that's more breathable so you won't overheat. Not to mention it will be much easier to layer with a bomber or topcoat on a chilly day. Wear it buttoned up for a more tightly kempt look or unbutton it on the weekend with a pair of ripped jeans and sneakers for a weekend-casual ensemble.