Sienna Miller wore this trend very well and it is definitely a nice way to change the more retro styles with some added Jackie O classiness. Replace your eccentric brights with tortoise-shell sunglasses as they are so effortlessly chic with fabulously elegant appeal. It is most perfect for sunny days as well as the colder fall season as it is just subtley yet incredibly oh-so-fabulous. It is a must-have in my handbag. Plus, if Sienna Miller can do it; why can't you? Pulling off tortoise-shell sunnies are easier than you think. Trust me on this one.