Ensure personal comforts by settling down? (7,4,4)
I believe the answer is:
feather ones nest
'ensure personal comforts' is the definition.
(to feather one's nest is to selfishly make money)
'settling down?' is the wordplay.
I cannot quite see how this works, but
'down?' could be 'feather' (down is a kind of feather) and 'feather' is located in the answer.
This may be the basis of clue (or it may be nonsense).
'by' is the link.
(Other definitions for feather ones nest that I've seen before include "Accumulate wealth" , "make money dishonestly?" , "become richer" , "How one may get down" , "Enrich oneself" .)