There have been several mentions on these boards about Quentin Tarantino (who I guess is pretty much washed up now?)
Fritz Lang, who directed Joan Bennett in four 1940s movies, visited the studio & coached Joan on her DS role.
KLS in her first book which is now long out of print said that when Lang was visiting the set, he "made a few lighting suggestions" which were instantly used. I thought THAT was very cool.