Master the last of skills needed with fish (7)
I believe the answer is:
skipper
'master' is the definition.
('skipper' can be a synonym of 'master')
'the last of skills needed with fish' is the wordplay.
'the last of skills' becomes 's' (I can't explain this - if you can you should give a lot more credence to this answer).
'needed with' says to put letters next to each other.
'fish' becomes 'kipper' (type of fish).
's'+'kipper'='SKIPPER'
Can you help me to learn more?
(Other definitions for skipper that I've seen before include "Shakespeare's giddy youth" , "Captain - one using a rope" , "team leader" , "Trawler boss" , "Captain of team or boat - type of butterfly" .)