Proportion

Proportion, Proportion, Proportion.

I'm not going to tell you to run out and buy a Dolce & Gabbana suit, but this ad shows what can be done with proportion. What's the difference between the man on the far right and the one next to him? Proportion. The longer collar on the middle-right guy is the correct proportion to the width of the tie. The man on the far right has a collar that looks strange now, and will in 10 years, too.

So, if you want to wear a skinny or wide tie, just check the collar proportion to see if it works.