Working hard at the workshop ourselves (8)
I believe the answer is:
studious
'working hard' is the definition.
(I've seen this before)
'at the workshop ourselves' is the wordplay.
'at' is a charade indicator (letters next to each other).
'the workshop' becomes 'studio' (I've seen this in another clue).
'ourselves' becomes 'us'.
'studio'+'us' is 'STUDIOUS'.
(Other definitions for studious that I've seen before include "working hard" , "Deliberate and painstaking as in reading" , "with great care" , "Bookish, sedulous" , "Diligent; scholarly" .)