Some final lessons? Everything considered (2,3)
I believe the answer is:
in all
'everything considered' is the definition.
('in all' can mean taking into account everything)
'some final lessons?' is the wordplay.
'some' says the answer is hidden in the clue (some parts of the word are used).
'IN ALL' is hidden in the letters of 'final lessons'.
(Other definitions for in all that I've seen before include "totally" , "after considering everything" , "Taken as a whole" , "In total" , "Everything considered" .)