People new to the game of wearing a tie have it wrong. Well, they're wearing a tie right, but it's about the shirt. Casual shirts DO NOT WORK. Casual shirts are meant to be worn without a tie. They typically have floppy collars, and are fitted in S,M,L, which results in an inappropriate sleeve length and TERRIBLE collar fit. The collar is bound to be too big (not often the case for those with fitted shirts) or too small (I see this a whole lot more).
Because the collar doesn't fit, we see a lot of kids rocking the loose tie... before hours. This is blaspheme. This results in looking affected, and reminds me of walking about with your fly down. The tie comes loose after hours bro, when your date is so hot you can't handle it (well, maybe not, but we can wish).
Also, S,M,L dress shirts can be the downfall of many a folk. The fit is typically off and even if the collar is stiff, it won't look as clean cut as you would hope. Know your collar size and know your sleeve length, then hit up Lands End, Brooks Brothers, or LL Bean to find a shirt that fits.
Sidenote: To all those 'skinny' guys out there, you won't swim in a LL Bean slim fit or a Land's End tailored fit, BoO has just trained you to think so. Tuck your shirt in, and you'll see how amazing a LL Bean or Land's End oxford can be.
Sidenote 2: GQ has more info here.