Thoughtfully consider friend about to prepare for publication (8)
I believe the answer is:
meditate
'thoughtfully consider' is the definition.
(to meditate on something is to consider it)
'friend about to prepare for publication' is the wordplay.
'friend' becomes 'mate' (mate is a kind of friend).
'about' indicates putting letters inside.
'to prepare for publication' becomes 'edit' (I've seen this in another clue).
'mate' enclosing 'edit' is 'MEDITATE'.
(Other definitions for meditate that I've seen before include "Cogitate" , "Ponder" , "Focus one's mind for a period for spirituality or relaxation" , "Think contemplatively" , "Think intently and at length" .)