Cobblers start to nail, working by feel (8)
I believe the answer is:
nonsense
'cobblers' is the definition.
(I've seen this before)
'start to nail working by feel' is the wordplay.
'start to' indicates taking the first letters.
'working' becomes 'on'.
'by' means one lot of letters go next to another.
'feel' becomes 'sense' ('sense' can be a synonym of 'feel'**).
The initial letter of 'nail' is 'n'.
'n'+'on'+'sense'='NONSENSE'
(Other definitions for nonsense that I've seen before include "Rubbish; absurdity" , "Rubbish, twaddle" , "Foolish or meaningless words" , "Baloney" , "Gobbledegook" .)