I think what makes her so stunning is that unlike her American counterparts, the Hollywood Royalty, she keeps it classy...No nip slips or lady part shots for Kate! Plus she is always flashing a megawatt smile...but then again, who wouldn't be in her shoes? Isn't she living out every little girls fantasy?
Rule One: Accentuate your best asset. In Kate's case, she has a rockin bod and knows what's best for her body, so she focuses on her waist.
Rule Two: When in doubt, wear a blazer. Sophisticated, tailored, and polished. Throw it on over just about anything and Voila! instantly sleeker.
Rule Three: Know how to counterpoint. Kate is all about the hats and headpieces. Pair a 'fun' item with something more classic. It's all about knowing the rules and knowing when to break them.
Rule Four: Keep colors in mind. Just like Jennifer Aniston, Kate sticks with neutrals. Black, white, grays, and blues. Only when she really wants to pop i.e. Special Occasions, she pulls out the brights.
Rule Five: Confidence is Key. If you look confident in what you are wearing, have a huge smile on your face, and are willing to take style risks unapologetically, everyone will take notice. Nobody likes the sourpuss, "woe is me" celebrity or commoner for that matter :)