Flies catch more fly fishers than fish … have a small selection of flies you have confidence in.
In clear water I like to use natural coloured flies that have the same form and function as the yellowfin bream’s natural food and in coloured water I’m happy with brighter flies.
Yellofin bream will feed from the surface to the bottom and all depths in between but generally hold at depths where they have some sort of cover.
Given that yellowfin bream eat mainly prawns and shrimp, molluscs such as oysters, worms and to a lesser extent small fish and crabs it’s not surprising that the best of flies for yellowfin bream are representations of prawns and shrimps preferably tied on size #2 in summer and up to #1/0 hooks in winter.
Traditional flies such as a Clousers, Crazy Charlie and Baited Breath fly still work for yellowfin bream as do some bonefish flies such as Gotcha’s and CXI specials and some bass flies such as Bass Vampires. Here are some other options:
Mud prawn 
Mutant clouser 
PET prawn 
Estuary fly 
Baitfish bugger 
PET nipper