Recommended arrangement for Dave and Sid (7)
I believe the answer is:
advised
'recommended' is the definition.
(I've seen this before)
'arrangement for dave and sid' is the wordplay.
'arrangement for' indicates anagramming the letters (I've seen this in other clues).
'and' says to put letters next to each other.
'dave' after 'sid' is 'siddave'.
'siddave' with letters rearranged gives 'ADVISED'.
(Other definitions for advised that I've seen before include "Did guide" , "Sensible; recommended (a course of action)" , "Informed" , "Counselled" , "Gave guidance to" .)