A well balanced face and body. Small ears, nose and a good jawline helps, but isn't neccessarily essential. A long neck works well with the shortest styles that give you absolutely nothing to hide behind, but basically if you like your face, you should love your hair short.
Just look at natural beauties like Jamie Lee Curtis... A good stylist should be able to help you with your new selection of style. Pay attention to the details and if your wondering just how you'd look with short hair prior to the shears drop me a line for some free hair imaging. I'll give you my details of what I need in the way of a pic to "make you over" then.