Golden rules for styling celebrity clients for big events?

My 'practical' golden rule is that the look should be perfectly tailored, and my 'magical' rule is that whoever is wearing it feels fantastic in it. he right underpinnings are very important too.
Favorite brands for cocktail attire?
Brands I go to again and again are Giorgio Armani, Alexander McQueen, Valentino, Prada, Gucci, and Wolk Morals.
What's your ultimate day-to-night essential?
I love a jumpsuit - it's the easiest to transform with accessories for day into night. Adding sparkle is one of my favorite tips... Who doesn't love a little sparkle?