same tactics as you use for carp. Koi and carp are the same thing besides the genetic color mutation in the koi. Easiest was is to get a can of sweet corn. Whatever you do do not get the salt free corn the koi/carp love the flavor. Then take half a can to a can of corn chum the area you see activity and then toss your lines out. Also remeber to keep chumming even when your lines are out there because those carp will clean that corn right up. Good luck buddy