Turner for example, follows assistant, showing some polish (6)
I believe the answer is:
patina
'some polish' is the definition.
(thesaurus)
'turner for example follows assistant' is the wordplay.
I cannot really see how this works, but
'turner' could be 'tina' (Tina Turner, famous singer) and 'tina' is present in the answer.
'assistant' could be 'pa' (personal assistant) and 'pa' is found within the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
'showing' acts as a link.
Can you help me to learn more?
(Other definitions for patina that I've seen before include "Green coating on bronze" , "Surface film on ancient bronze" , "Fine coating on surface" , "Surface film formed by age" , "Developing surface film; sheen" .)