The consultant who selects the entire look of a celebrity is the costume stylist. They choose the piece of clothing that the star needs to wear and the way they need to drape the outfit. They counsel them for the way they shall carry it off as well. They study the character of the actor for a film and the background of the role. They start with the primary aspects of the costume like the dress material and color schemes and patterns and then communicate with the costume designers. They discuss their ideas with the fashion designers and the make-up/ hair stylists as well.
The role played by the actor depends on their acting skills, but what enhances their performance is the way they look on screen. From their costumes and jewellery(or any other accessory) to their make-up and hair, everything needs to get well with each other and with the character they play on screen. They have great knowledge in clothing- colors, textiles, and the costumes that are local to a specific region. They need to keep a check on the cost and complete their tasks before the sequence hits the floors. They also have to find out the actor's ability to wear the selected outfits confidently.