Here is a scenario.Find carp that are bunched up AND feeding,the competition factor will throw their guard down,the trick is learning when fish are truly feeding and when they are not.Disregard the non feeders,your wasting your time(also follow previous post about spawning carp,they drive you nuts with their radical behavior/non-feeding).Avoid flies that need movement until you get more familiar with carp behavior.Here is my recomendation, San Juan worm,red with gold bead,or my own version that has a blue glass off-set bead on red body.Caught my first Montana fish of the year with this last fly,found a hog that jumped on it to beat another fish.Drop the fly comfortably in front of a foraging fish, and wait for the fish to move up onto the fly,when it hesitates,wait a split second and then tighten the line.If you have carp in moving water,(trout type moving water), sight fishing with crawdad patterns and white buggers have been good to me on the Missouri.Lead a fish in the current with the bugger so it can sink to their level, and strip it right past their nose,I've had fish follow the white fly for5-6 feet and suck it in(the joy is watching the white fly disappear).The thrill of catching carp,I think,is learning how to fool them,then the reward of powerful fish burning into your backing.The essence of fishing,sure, but at a whole new level.