Here is an example of a basic suit. It's simple yet classy. Do not forget the tie clip! A floppy tie is enough to bring your whole look down. Also, a fitted shirt is key. You don't want to look like you are swimming in your clothes.
Clean shirt, new shoes And I don't know where I am goin' to Silk suit, black tie, I don't need a reason why They come runnin' just as fast as they can 'Cause every girl crazy 'bout a sharp dressed man -ZZ Top