Every wonder how you should wear your shirt, or how big your suit jacket should be? Well How Clothes Should Fit is a cool site based on a reddit booklet that does just that. It gives you a great quick summary of how to wear your dress shirts, pants, shoes, suits, and even jeans. Here is a small blurb from the site:
The collar should just graze your neck without constricting it. If turning your head causes the collar to turn with it, the collar is too tight. You should be able to comfortably fit two fingers inside of your buttoned collar without it tightening against your skin.
Your cuffs should meet the point where your palm begins (about 2cm up from your wrist bone). It should be tight enough that your thumb notch at your wrist will stop the cuff from moving up your hand. It should be a bit looser than a properly fitting watch, and not go farther up your wrist than that watch.
The shoulder seam should be at your shoulder bone. This is the point on your shoulder that is the greatest distance away from your sternum.
Take a peak, it is well worth the 5 minute read and bookmark.