i'm no expert, but have fooled with blue sharks a couple times.
the first trip we had great calm conditions which aided in spotting the sharks behind the chum and allowed up to really dead-drift the chum flies well. the second trip had 25 knot winds which made spotting any sharks impossible and we didn't hook any one flies.
when the first sharks showed up on that first trip, we hooked one on a FT clouser tied on a 5/0 gami hook... after that though we couldn't get any grabs on streamers and or poppers. what worked best was tossing some chunks of mackerel and then following the chunks with a red and yellow marabou chum fly on the same hook as above (i didn't palmer the marabou, just tied it down on the top and bottom of the hook shank alternating between red and yellow. we hooked 3 more that way, with a couple grabs as the chum fly just trailed behind the boat (not dead-drift).
i'm sure in the future i'll play with some of the larger flies being talked about, but thought i'd mention some smaller flies (at least in length) that worked.... but maybe there's some difference in east coast vs. west coast sharks and/or their feeding preferences. the size of the chum flies i was using might be similar to some of the large winter-steelhead patterns.