Ok, here we go. Now I am rather new at this myself, but this has been my experience. Flatheads go for 1 lb to 3 lb carp. Any bigger and I get muskie hits all the time. We don't want muskies (at least I don't), we want 40 - 60 lb plus flatheads.
Hooks. I hook carp and sheephead behind the dorsel fin always. No exceptions. You need a wide gap hook for this. Buy an assortment of 17/0 to 20/0 Sea Circle Hooks from CatfishConnection.com. I buy by the hundreds and paint them red with paint that is non-toxic and environmentally friendly. I add juice from fresh cherries to give the hooks a deep red color. Little technique I picked up from a wise man. Colors I experiment with are blue, chartreuse, and purple. I've gotten hits on all of them.
Position the hook so the barb will NOT hook back into the flesh of the fish...but keep it deep enough so the carphead is secured and won't try any funny business like getting off your line. I use 8-20 ounces of weight depending on current, size of bait, and overall castability. I try to use flat, pancake sinkers or lots of spoon shaped ones to do the job.
When using carp, I use 60 lb dacron with a steel leader. Reason being if I get a muskie hit, I want my hook back and I don't want the muskie. Also, dacron will not stretch much. Make sure you have a saltwater barrel swivel on that baby that can hold a lot of weight and will not break. If you find the fish is not loading up on the hook before you pull back, then gently, with a channel lock pliers, bend the barb side of the hook out, but don't bend the barb, if you know what I mean. Either that, or increase the size of your hook and the gap between hook and carp flesh.
Words from the peanut gallery,
James