One amongst majority to get prominent about source of ugly work with cosmetics? (10)

'work with cosmetics?' is the definition.
(put moisturiser on)

'one amongst majority to get prominent' is the wordplay.
'one' becomes 'i' (Roman numeral).
'amongst' is an insertion indicator (I've seen this in other clues).
'majority' becomes 'most' (most of a group).
'to' becomes 'u' (I can't explain this - if you can you should believe this answer much more).
'get prominent' becomes 'rise' (rise can mean to become prominent).
'i' put within 'most' is 'moist'.
'moist'+'u'+'rise'='MOISTURISE'

'about source of ugly' acts as a link.
This may not be right. Some or all of it may be part of another bit of the clue.

Can you help me to learn more?