Prepare to rent piece of jewellery (8)
I believe the answer is:
bracelet
'piece of jewellery' is the definition.
(bracelet is a type of jewellery item)
'prepare to rent' is the wordplay.
'prepare' becomes 'brace' (bracing is a kind of preparing).
'to rent' becomes 'let' ('let' can be a synonym of 'rent').
'brace'+'let'='BRACELET'
(Other definitions for bracelet that I've seen before include "Might Bel react badly to this jewellery?" , "Ornamental wristband" , "Ornamental band worn on wrist" , "Item of jewellery found in Crete lab" , "charm?" .)