It's safe to assume that most men have a couple pairs of jeans, some T-shirts, a sweatshirt or two, and maybe a few button-down shirts in their wardrobe. If you don't have those, you're either unusually well-dressed or very inventive.The way to go from looking like everyone else to looking sharp and stylish is to take those basic wardrobe pieces and swap a few of them out for pieces that are nicer, but aren't necessarily any more formal. When everyone else is wearing jeans and T-shirts or…