Make leather with good smell (4)
I believe the answer is:
tang
'smell' is the definition.
(I have seen 'Strong smell' mean 'tang' so perhaps 'smell' could also mean 'tang')
'make leather with good' is the wordplay.
'make leather' becomes 'tan'.
'with' is a charade indicator (letters next to each other).
'good' becomes 'g' (abbreviation).
'tan'+'g'='TANG'
(Other definitions for tang that I've seen before include "Distinctively sharp taste" , "Thrash with good" , "Strong smell of gnat" , "Bite" , "Strong taste or smell" .)