I use the berkley gulp shrimp on the top hook and minnow/squid on the bottom hook. The shrimp catches twice the fish as min/squid. I hook them though the head on a hook with beads and spinner blade on it.
I like fishing them on 3/4 oz - 1oz chartreuese jigs tied in tandem. There is something about the spec rig configuration that triggers more strikes. I have caught my largest flounder on almost every trip this year on this rig. It's alot more fun catching flatties on jigs anyway.
For more shallow water use as light of jig head as possible and start with a 1/4 oz. If the current won't let it hit bottom increase in weight but go with as small as possible. I like the white or chartruese 4" curly tails, especially at night. ;-)