When I research a look for an icon or a celebrity I build a collection of images from different angles and different periods of their career.
I then study the pictures to find the similarities that would determine the subjects signature look.
From the pictures above you can see that :-
1) Marlene changed the shape of her eyebrows from her early days probably due to fashion. However, her eyebrows always remained thin, dark and defined.
2) The socket line was always very defined and blended.
3) Likewise, the cheeks were contoured and highlighted to give a very sculpted finish.
4) Liquid (Cake) liner was always present and flicked.
5) Marlene left the underneath of her eyes bare apart from a flesh coloured eyeliner on the waterline. This adds to the heavy lid quality.
6) The top lip is always rounded and the lips were red.