Usuallt the Channel classic sunglasses will fit all kinds of face shape. No matter you have the long face, round face, square face or the pointed face, you will look good on this type of sunglasses. Besides the accessory role, the main role of sunglasses is to help you protect the eyes from strong light and uv.
Well, it all depends on what face shape you are. Generally speaking, if you have square face shape, you can try the oval or round frames. And if your face is heart shaped, you can choose the round frames, because Shapes with round edges look great (on heart shaped faces) and soften the broad upper part of your face. Besides, if you have long face, you can wear some long frames which will match your face perfectly. Anyway, there is nothing to do with which brand of sunglasses you wear, but what kind of frames you wear. So you should wear them according to your face shape.