Every guy should know their measurements when it comes to suits, dress shirts, and slacks. You can try to measure yourself, or have a friend do it, but this requires you to learn the correct methods and steps to obtaining a proper measurement. Just find a highly rated tailor online in your area, make an appointment, and go get all your measures done professionally and accurately. This will allow you to buy correct sizes in the future, which in turn will make you appear more polished and slimmer. Nothing is worse than trying to look your best, and then finding out you're wearing the wrong sizes. This is an easy fix.