For the most part, I carp in target rich environments. It is not uncommon for me to see a hundred (or more) carp in a full day of fishing. Granted, I tend to cover a lot of water but carp are a schooling fish...you aren't really going to find just one fish very often (but if you do, congratulations...it is probably a monster).
So what do you do with so many targets? It can be more than a bit overwhelming. One year I slipped into an area with a buddy and we were instantly surrounded by dozens and dozens of carp. The water thrashed with spawning, feeding and cruising carp and I watched my buddy frantically flipping flies here, there and everywhere, barely giving the fish time to find the fly before another target presented itself and he moved to that fish. I quickly reminded him to take a breath, slow down and fish to one fish. I watched as he gathered himself, made a perfect cast and hooked up nearly instantly.
The simple truth of the matters that not all carp are going to eat your fly. These aren't trout people...you are not going to"talk them into eating" very often. Yes, it can be done (my personal favorite is the mustache technique) but in general, a carp is either in the mood or it isn't.
A few years ago I made a conscious effort to cast at less fish. What happened? I caught more. Pretty simple really. If I was reasonably certain I was looking at a negative fish, I skipped it. Why cast at a fish that is likely to spook and blow a bunch more fish in the process? In those situations you are better off sneaking past the fish and finding another target.
Not always easy to do. I sat with my old high school basketball coach Julio for over and hour one day, casting at sunning carp that were clearly negative because he simply couldn't walk past them. Within ten minutes of leaving we spotted a slow cruiser and he nailed that fish. Despite the logic of having so many targets, it simply doesn't add up to cast at negative fish. And possibly the toughest fish to let go? A blown feeder. Take it from me, if you are casting to a tailer or slow cruiser and the fish makes you or the fly and starts to vacate the area...DO NOT throw one last cast after him. Look, if the fish is onto you it ain't going to eat, and that last cast can change the attitude from, "something ain't right" to "holy shit an eagle!". The last thing a stealthy, buff covered ninja carper needs is a hole in the water big enough to spook every carp within 100 yards.
If you want to catch more carp, cast at less.