Part of pin’s head turned up covered in glitter (8)
I believe the answer is:
shinbone
'part of pin's' is the definition.
'shinbone' can be an answer for 'part' (shinbone is a kind of part). I'm not sure about the 'of pin's' bit.
'head turned up covered in glitter' is the wordplay.
'head' becomes 'nob' (I've seen this in another clue).
'turned up' shows that the letters should be reversed in order.
'covered in' is an insertion indicator.
'glitter' becomes 'shine' (synonyms).
'nob' written backwards gives 'bon'.
'bon' inserted into 'shine' is 'SHINBONE'.
Can you help me to learn more?
(Other definitions for shinbone that I've seen before include "It is also called the tibia" , "that supports member" , "The less formal tibia" , "bit of leg" .)