Difficult making a bow without beginning on ribbon (6)
I believe the answer is:
trying
'difficult' is the definition.
(similar in meaning)
'making a bow without beginning on ribbon' is the wordplay.
'making a bow' becomes 'tying' (tying a bow).
'without' is an insertion indicator ('without' can be similar in meaning to 'outside').
'beginning on' suggests taking the first letters.
The first letter of 'ribbon' is 'r'.
'tying' placed around 'r' is 'TRYING'.
(Other definitions for trying that I've seen before include "job for a jury?" , "Hearing (a case)" , "Doing one's best - annoying!" , "Making an effort, or straining one's patience" , "irksome" .)