 Spacey loosely based Lester 's early " <unk> " <unk> on Walter <unk> . During the film , Lester 's physique improves from <unk> to toned ; Spacey worked out during filming to improve his body , but because <unk> shot the scenes out of chronological order , Spacey varied <unk> to portray the stages . Before filming , <unk> and Spacey analyzed Jack <unk> 's performance in The <unk> ( 1960 ) , because <unk> wanted Spacey to emulate " the way [ <unk> ] moved , the way he looked , the way he was in that office and the way he was an ordinary man and yet a special man " . Spacey 's <unk> is a <unk> to Sunset Boulevard ( 1950 ) , which is also narrated in <unk> by a dead character . <unk> felt it evoked Lester 's — and the film 's — loneliness . <unk> recalled women from her youth to inform her performance : " I used to <unk> constantly . You 'd go to church and see how people present themselves on the outside , and then be inside their house and see the difference . " <unk> and a hair stylist collaborated to create a " <unk> president <unk> " hairstyle , and <unk> and production designer <unk> <unk> researched mail @-@ order <unk> to better establish Carolyn 's environment of a " spotless suburban manor " . To help <unk> get into Carolyn 's mindset , <unk> gave her music that he believed Carolyn would like . He lent <unk> the Bobby <unk> version of the song " Don 't Rain on My Parade " , which she enjoyed and persuaded the director to include it for a scene in which Carolyn sings in her car . 
