1980 thriller starring Michael Caine and Angie Dickinson that surprisingly didn't win an Oscar for best costume design? (7,2,4)
I believe the answer is:
dressed to kill
(Other definitions for dressed to kill that I've seen before include "smartly attired" , "Wearing clothes intended to make one look drop-dead gorgeous" , "in armour?" , "in fine threads" , "Done up to the nines" .)