Due roughly after fitting - it shows talent (8)
I believe the answer is:
aptitude
'talent' is the definition.
(I've seen this in another clue)
'due roughly after fitting it' is the wordplay.
'roughly' indicates an anagram.
'after' is a charade indicator (letters next to each other).
'fitting' becomes 'apt' (I've seen this before).
'due' is an anagram of 'ude'.
'apt'+'it'='aptit'
'ude' put after 'aptit' is 'APTITUDE'.
'shows' acts as a link.
(Other definitions for aptitude that I've seen before include "capacity" , "Update it, having natural skill" , "Flair" , "Bent" , "Natural ability or skill" .)