Picture about final to catch a carrier (7,3)
I believe the answer is:
plastic bag
'carrier' is the definition.
(I've seen this before)
'picture about final to' is the wordplay.
'picture' becomes 'pic' (short for picture).
'about' indicates putting letters inside.
'final' becomes 'last' (synonyms).
'to' becomes 'bag' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'pic' going around 'last' is 'plastic'.
'plastic'+'bag'='PLASTIC BAG'
'catch a' acts as a link.
This may not be right. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for plastic bag that I've seen before include "Supermarket shopper" , "Shopping carrier?" .)