On the right and below is two different kinds of carp archery targets. One is a paper target you can use for practicing for bowfishing, the other is a 3D foam target of a carp.
Regardless of whether you use a paper target or a foam target for practice, it is very important to practice your bowfishing skills before actually going bowfishing.
Hence why having a target is so handy.
And with respect to fly fishing, well then it is best you know your equipment really well and how to use it properly.
The video below will show you how to catch, clean and cook carp - the catching part is fly fishing - and they also show the "ethical way to kill carp", which is to freeze kill it in a bucket of ice. The cooking part is more gentile - myself I would probably put it on a stick and roast the fish meat over a campfire - but to each their own.