Taking the trouble to be thrifty (7)
I believe the answer is:
careful
'thrifty' is the definition.
(synonyms)
'taking the trouble' is the wordplay.
I cannot quite see how this works, but
'trouble' could be 'care' and 'care' is located in the answer.
The remaining letters 'ful' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
'to be' is the link.
Can you help me to learn more?
(Other definitions for careful that I've seen before include "Thorough" , "Painstaking" , "Guarded" , "Thrifty" , "Attentive" .)