Warm to winner, setter and dandy (3,2,3)
I believe the answer is:
hit it off
'warm' is the definition.
I know nothing about this answer so I cannot tell whether this works.
'winner setter and dandy' is the wordplay.
'winner' becomes 'hit' (both can mean a successful creative venture).
'setter' becomes 'i' (the person that set the crossword).
'and' says to put letters next to each other.
'dandy' becomes 'toff' (I've seen this before).
'hit'+'i'+'toff'='HIT IT OFF'
'to' acts as a link.
Can you help me to learn more?
(Other definitions for hit it off that I've seen before include "Become immediate friends" , "Get on well with - or knock from position?" , "Be well suited" , "Get on well - with a blow?" , "Click with someone" .)