I recently went to the Hollywood Costume exhibition at the Victoria & Albert Museum in South Kensington, as a huge fan of film, fashion and costume it was such a brilliant exhibition to visit; I really can’t recommend it enough.
The costumes are exhibited on manneqins with a head shot of the actor who played the part, the story board of why that exact look worked so well for the character, and then some costumes have interviews with the actors/directors/costume designers; it is exceptionally thorough.
ABOUT THE EXHIBITION: http://www.vam.ac.uk/content/exhibitions/exhibition-hollywood-costume/about-the-exhibition/