How long should the sleeves be?
This by far is the most misunderstood part of putting on a suit. The sleeves of a suit should be as long as you feel comfortable with. The rule of thumb is that you should see about half a centimeter of the shirt when you stand straight and up to two centimeters when you raise your hands. This is something that is different from person to person. When you decide the length of the arms of your jacket you should consider where and in which situations you are going to use the jacket most of the time.
Some people use the jacket only outside where they are walking or standing. This means that the jacket can be altered giving the thought that it mostly will be used in standing and going situations. So a little shorter than usual.
Some people use the jacket inside and in the meetings where they use their hands as a part of their communication. They have their arms raised above the waist all the time. This means that you should spare a cm or two on the length of the sleeves because you don't want the jacket to be short on your arms when you are raising your arms. So a little longer than usual.