Better being done humbly (3,2,4)
I believe the answer is:
cap in hand
'humbly' is the definition.
(as in the phrase 'coming cap in hand')
'better being done' is the wordplay.
'better' becomes 'cap' (I've seen this before).
'being done' becomes 'in hand' (if something is 'in hand' it is being done).
'cap'+'inhand'='CAP IN HAND'
(Other definitions for cap in hand that I've seen before include "unassumingly" , "Go bareheaded thus to be obsequious" , "Go . . . . . . . . . to beg humbly, clutching headgear?" , "Humbly asking a favour" , "with humility" .)