Look towards rule to control depth for foundation (4,6)
I believe the answer is:
face powder
'control depth for foundation' is the definition.
I can't tell whether this definition defines the answer.
'look towards rule' is the wordplay.
'look' becomes 'face' (synonyms).
'towards' says to put letters next to each other (I've seen this in other clues).
'rule' becomes 'powder' (I can't explain this - if you can you should believe this answer much more).
'face'+'powder'='FACE-POWDER'
'to' acts as a link.
Can you help me to learn more?
(Other definitions for face powder that I've seen before include "Make-up" , "Cosmetic preparation" .)