Suit wearing decorum is equally vital as design, color, and brand. Being ignorant about matching accessories or pairing the correct socks with a suit makes you very vulnerable to situations where you might appear silly or incompetent.
Consider the accessories worn with your suit. There are a few basic considerations here. Your belt should match your shoes. The only charms worn with a suit should be cuff links, tie tack, and a watch. Though not very common now, some men carry a handkerchief in their upper chest pocket.
That's all the basics for suit wear in today's day and age. Now you can avoid some familiar mistakes and blunders and look your best.