Establishing a signature style can be a great way to make a statement, as many celebrities know. But it can also turn into a rut. Look to these best and worst examples for clues on how long you should stick with your signature style and if it's really right for you.

Rihanna owns her sassy short cut with a long angled fringe. The long layers on top give her amazing versatility.

The "cat eye," is now the Angelina Jolie eye to many women. When you find a makeup style that makes the very most of what you've got, stick with it. You can vary your look with different liner colors and lip colors.

Paris Hilton's high-maintenance look has her in a rut. We'd love to see her drop all the artifice and run out the door in bronzer and a messy ponytail.

Michelle Williams is a style icon dark horse. She has perfected the essence of nonchalance with her varied casual updos and minimalist makeup. But her look never gets boring.