Accept it's the way to make clothes fit better (6)
I believe the answer is:
takeup
'way to make clothes fit better' is the definition.
I know nothing about this answer so I cannot judge whether this works.
'accept it's' is the wordplay.
'accept' becomes 'take' (to accept is to take possession of).
'it's' becomes 'up' (I can't justify this - if you can you should believe this answer much more).
'take'+'up'='TAKEUP'
'the' acts as a link.
Can you help me to learn more?
(Another definition for takeup that I've seen is " Adoption".)