Smooth finish on some attire (5)
I believe the answer is:
habit
'attire' is the definition.
(I know that habit is a type of attire)
'smooth finish on some' is the wordplay.
'finish' indicates one should take the final letters.
'on' means one lot of letters go next to another.
'some' becomes 'abit' (both can mean a small amount).
The last letter of 'smooth' is 'h'.
'h'+'abit'='HABIT'
(Other definitions for habit that I've seen before include "Breaking this is hard" , "Monk's garb" , "nun gets into" , "Addiction to a drug" , "Custom; riding dress" .)