Mess about with some trinkets (6)
I believe the answer is:
tinker
'mess about' is the definition.
(I've seen this before)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for tinker that I've seen before include "Kettle-mender" , "Mender of pots and pans" , "Itinerant repairer" , "Itinerant pot mender" , "Make trivial changes" .)