Method is about right but be cautious (4)
I believe the answer is:
wary
'be cautious' is the definition.
(similar in meaning)
'method is about right' is the wordplay.
'method' becomes 'way' (way of doing something).
'is about' is an insertion indicator.
'right' becomes 'r' (common abbreviation).
'way' enclosing 'r' is 'WARY'.
'but' acts as a link.
(Other definitions for wary that I've seen before include "Cautious, suspicious" , "Displaying caution" , "Cautious and vigilant.17 Add up for infant" , "Cautious - vigilant" , "James Bond villain" .)