For best results (7)
I believe the answer is:
ideally
'for best results' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for ideally that I've seen before include "in theory" , "In the best possible way or circumstances" , "In the best possible scenario" , "In a perfect world, the best possible situation" , "Lay idle (anag)" .)