Picky types hold this stag party, getting nothing back (8)
I believe the answer is:
mandolin
'picky types hold' is the definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Maybe you can see an association between them that I don't see?
'this stag party getting nothing back' is the wordplay.
'this stag' becomes 'man' (I can't explain this - if you can you should believe this answer much more).
'party' becomes 'do' (do is a kind of party).
'getting' says to put letters next to each other.
'nothing' becomes 'nil' (eg nil is zero in football).
'back' shows that the letters should be reversed in order.
'nil' backwards is 'lin'.
'man'+'do'+'lin'='MANDOLIN'
Can you help me to learn more?
(Other definitions for mandolin that I've seen before include "'Captain Corelli's - - '" , "Instrument resembling a lute" , "one's deployed in the kitchen" , "Stringed instrument, usually played with a plectrum" , "Round-backed musical instrument" .)