Music, clothes, makeup, models -- there are a lot of ingredients needed to whip up a successful fashion show, and a lot of people.

Today we start a new series "A Day in the Life Of..." to get to know some of the players behind the shows. They work long hours and they work hard in the weeks leading up to Fashion Week. It's not always glamorous, though admittedly more fun than many jobs.

We kick off with a profile of Romero Jennings, senior artist with MAC cosmetics, who has worked his magic on countless runways. In this video we see him confer with Carmen Marc Valvo on how to create his vision for Spring 2011 on the runway.