It is among the shaggiest medium length hairstyles. The effect of shagginess can be achieved by leaving the ends of your hair disconnected when styling it. Did you try this Shoulder-Length Shaggy Waves Hairstyle?
blunt cut with long layers. All hair was cut at one length with a few added long layers to create some extra body. Point cuts / razor cutting to create a softer rounded edge. Blow dry with round brush,