Picture Shaggy, shades on and a smile even wider cruising down the coast with the windows down in his sleek BMW M3. While it may not be a flamboyant ride, this car is all about understated cool.

A reinvention of the classic bob, this shaggy haircut is messy, full of texture and the key to sky-high volume. Here’s how to nail the hair trend. We know that it can be daunting to discuss ...