You're a casual guy. You don't dress up much for work, and your weekend uniform definitely doesn't go beyond a tshirt won't do the trick. Maybe you're able to pull something decent together, or maybe you fake an ailment and get out of it. Either way, the lesson here? No matter what your style is, every man needs at least one dress shirt and one polo shirt in their wardrobe.
The Dress Shirt
The dress shirt piece suit or a pair of jeans.
The Polo Shirt
Also called a golf or tennis shirt, the polo is short-sleeved, general made of cotton, has a two or three buttons and a collar. It's a great alternative to the dress shirt, when you need to dress up but don't want to go too fancy. Try pairing it with a nice pair of khakis, a brown belt and some brown loafers. Feeling even more casual? Combine it with some jeans and and a pair of sneakers for a sportier look. Speaking of sports, these shirts aren't just called golf and tennis shirts for nothing. Any place with a dress code, which most golf courses do indeed have, usually requires a collared shirt. So that's another reason to have one of these on hand; because when your boss invites you to go golfing, that Black Sabbath vintage tee will probably be even less of a hit with him than with your girl's parents.