tips for flathead fishing in lake martin AL

I take a trip to lake martin Alabama once every year or so but have only really been able to target channels and blues, got some other fish too but have only got lucky enough to stick a flathead once on a live worm. Last year i was using a bottom rig with a palm sized live bluegill and got picked up by something big in about 35-40ft of water and was then promptly ripped under a rock. Would love anybody to point me in the right direction for rigs, combo i need, line wt, baits, depths ranges, time of day, basically anything as I come from southern florida and the most we really get is bullheads.