Well, you should know that there is nothing to do with what brand of sunglasses, but with what kind of frames you will choose. It is really important to choose the right frame for each face shape. In your description, you have the square face. For square faces the goal is not to find hard angular lines that will accentuate your strong features, but to soften them with oval or round frames. So I think you can just wear the sunglasses which have the oval or round frames. Besides, except for the frames, you should pay more attention to the color of the sunglasses too. Anyway, just go to the store, there are professional persons who can give you perfect advices depending on your own condition and your needs.
It depends on how you make up yourself. You must know that Ray Ban aviator sunglasses are not just made in one style. They vary in different style. You can just go a ray ban store and try one some of them, and choose the best suitable one. Besides, you shall also wear clothes properly for a cool look. Anyway, you shall form your own value of cool or fashion. So, if you like it, just go ahead.
The design of ray ban aviator is so cool which attracts a lot of people and suits most people. In my own opinion, the ray aviator sunglasses will be suitable on your square faces. You'd better choose the one with the round lenses which may let your face look not that serious.