Many men wear ill-fitting clothes all the time. It is often not the clothes themselves, but rather the fit of them that determines whether or not they look good. You probably tend to just buying shirts by chest size — S, M, L, XL, etc. But when buying a dress shirt you must also pay attention to the size of the neck opening, the length of the arms and the broadness of the shoulders. Never wear a poorly fitted shirt again.
Know what to look for when buying the shirt: The first step in narrowing down what shirt to buy is the material it is made out of. No one wears polyester anymore. An all cotton shirt is the best choice — not only will it allow your skin to breath better, but the way the fabric looks and hangs on your body is nicer than any synthetic fabric.
Determine the chest size first: This is the probably the most important size to be looking for, and it is probably the size most men mess up when buying shirts. Chances are that all your shirts are one (or maybe even two) sizes too big for your body. This may have been the style years ago, but today it is most certainly not. There is no need to have the fabric billow around your body like a tent.
Having said that, you also must be careful about comfort; it looks equally as awkward to have a shirt so small that anytime you move, the fabric pulls tight. It should just simply fit your chest. If you are slender, then ask for a European cut or a lightly tapered shirt that is brought in at your thinnest section. Don’t worry about being too feminine — it does not look like that at all, but only makes you look thinner.
Here’s a good way to know if it fits right: when it is tucked in, does it billow out at the top of your pants? If yes, then it is too big.
Make sure the neck fits right: Any quality dress shirt will have the neck measurements printed on the label, but just for reference (or in case it doesn’t), you should be able to fit three fingers in between the shirt and your neck when it is fully buttoned up, with out any trouble at all.
Arm length is important too: If you plan to wear the shirt just by itself, with no jacket, then the bottom of the cuff can come only to the little indent right after your wrist bone. If you plan to wear the shirt with a jacket, then it should come a little further, about 1 1/2 inches past the indent after you wrist bone; this is so that a piece of the shirt will show even with your jacket on.
Make sure that when you outstretch your arms straight in front of you, the arms of the shirt don’t travel up too far. It is expected they will be a little shorter in this position, but they still need to be no further up the arm than your actual wrist bone, and they should not go further than the arms of the jacket do.
Broadness of the shoulders: This is an easy one to measure because there will always be a seam where the arms are sewn onto the body of the shirt. Now imagine that your shoulder and your arm are perfectly flat and extend out and up to create a square shoulder. Wherever that corner would be is where the seam should rest. In other words, just slightly after you shoulder drops and begins to curve downward is where this seam needs to sit.