Sometimes it's nice to dress up, sometimes you have to dress up, but whatever your reason, your driving rule should be less is more.
Simplicity is key when it comes to great tailoring and, unsurprisingly, Jon Hamm's style-fu is very strong in this department. Here he is at the premiere for the latest season of Mad Men, showing once again that he knows his way around a good suit.
The dark navy, two-button suit and wide-spread collar shirt are both excellent, but the real stroke of genius is the black tie. It might not seem like much, but the subtle change in color adds depth to the whole outfit without resorting to any "look at me!" shouty ties.