Cautious method is about right (4)
I believe the answer is:
wary
'cautious' is the definition.
(similar in meaning)
'method is about right' is the wordplay.
'method' becomes 'way' (way of doing something).
'is about' means one lot of letters goes inside another.
'right' becomes 'r' (abbreviation).
'way' enclosing 'r' is 'WARY'.
(Other definitions for wary that I've seen before include "Careful - cautious" , "Cautious - vigilant" , "Cautious of danger" , "Watchful" , "Cautious and vigilant.17 Add up for infant" .)