Your info seems correct, remember they are ambush predictors so they will hit pretty much anything that dangles over their head should that be your bait or jig.
I don't fish for them often enough with bait but when i do i find that drifting over weedbeds, flats and drop offs the best, meaning that your boat will cover ground naturally casting to either side of your boat.
When fishing for them with SP's I find that fishing the flats on the falling tide is better than fishing the flats on the rising tide but thats just my opinion, look for structure, fish the edge of weedbeds, deep water holes and areas where there is current flow.
Also when fishing with SP's remember to slow the retrieve down, right down add pauses if you need to, make sure that the plastic hits the bottom and hold your line to detect 'hits' once you get a hit lift your rod and hook the fish.
I dont know how you lost your flattie but be aware that the flathead has sharp spikes on the side of their head which can easily shred the line when landing the fish, avoid lifting the fish up as the flathead has a tendency to thrash around by shaking their head resulting in lots of thrown hooks.
Good luck in time you will be an expert in fishing for flathead.