When using braid I normally use a mono leader that matches what I am trying to catch. If I am looking for deep water pan fish the leader will be either 6 or 8 pound test. If I am trying to catch cod, haddock or pollock in the ocean the leader is 50 pound mono on 65 or 80 pound power pro. Normally unless I am fishing in very deep water I don't use braid or need a leader. Shallow water pan fish I use either 4 or 6 pound straight mono. I seldom mess around with fluorocarbon line.