I came across this 2014 obit while looking for a pic of Dustin Hoffmann as the 121 year-old man. The guy pretty much wrote the book on makeup. When I was singing in an opera chorus in the 1970's & 80's I had his book and it was amazing (and went far beyond anything I ever needed.)
The article goes into some detail and is worth reading.
"Dick Smith, considered Hollywood's pre-eminent master of film make-up who made a young Dustin Hoffman look like a 121-year-old man and who made Linda Blair's head spin in The Exorcist, died last week in Los Angeles. He was 92.
Smith, who was entirely self-taught, devised many of the innovations that redefined movie make-up artistry, including new ways to create age-lined faces and to depict blood spurting from bullet wounds. Even his formula for fake blood, using corn syrup and food colouring, has become the Hollywood standard....
Among his many accomplishments, he made Marlon Brando over into an ageing Vito Corleone in The Godfather (1972); he reshaped William Hurt's body into an amorphous blob in Altered States (1980). And he horrified moviegoers with stomach-churning special effects in The Exorcist (1973), in which a girl is possessed by the devil....
F. Murray Abraham as Antonio Salieri in Amadeus
Dustin Hoffman in Little Big Man
"The nose was separate from the chin, the ears were distinct pieces from the forehead and eyelids. Each element is called an "appliance" because it is applied to the skin. It was something entirely new in film make-up.
It took five hours each day for Smith to put on Hoffman's face, but the result was that the actor's expressions were clearly visible under the make-up."
Smith, who was entirely self-taught, devised many of the innovations that redefined movie make-up artistry, including new ways to create age-lined faces and to depict blood spurting from bullet wounds. Even his formula for fake blood, using corn syrup and food colouring, has become the Hollywood standard....
Among his many accomplishments, he made Marlon Brando over into an ageing Vito Corleone in The Godfather (1972); he reshaped William Hurt's body into an amorphous blob in Altered States (1980). And he horrified moviegoers with stomach-churning special effects in The Exorcist (1973), in which a girl is possessed by the devil....

F. Murray Abraham as Antonio Salieri in Amadeus

Dustin Hoffman in Little Big Man
"The nose was separate from the chin, the ears were distinct pieces from the forehead and eyelids. Each element is called an "appliance" because it is applied to the skin. It was something entirely new in film make-up.
It took five hours each day for Smith to put on Hoffman's face, but the result was that the actor's expressions were clearly visible under the make-up."

The article goes into some detail and is worth reading.