to match your shoulder length hair, you can try black oversized square sunglasses that make you look Intellect beauty. Again, oversized round sunglasses and some bright colored framed rectangular sunglasses can also match people with shoulder length hair. As for which are the best sunglasses for you, you need think about your face shape and temperament. Just try on and find the best suitable sunglasses to compliment you.
Shoulder length hair is neither too long nor too short. People with shoulder length hair can try sunglasses with large frame and brightly colored sunglasse. In addition, wide frame sunglasses can also go well with shoulder length hair. However, that is only my suggestion. You can go to any optical store to select different styles of sunglasses to try them on. Then you can decide what kind of sunglasses would match with your shoulder length hair. Or you can ask for the seller's opinion, too.