But you should all go see The post where I got this one, which is by diet, because she does something really interesting I think.
Because making icons out of manga images, no matter how gorgeous they are, is tough if you don't want them to be all black and white. Most people add color to the images themselves, myself included, and it works just fine usually, but it does change the tone of the art, the mood, etc.
diet takes the opposite route and makes the background crazy funky colors, leaving the black and white image on top, which makes it pop a little, and does not change the feel of the art so much. I really like this idea, and i think this batch is really cool.
so anyway, that's my two cents about iconning with manga. Perhaps I will give this method a shot next time i do a batch, and we'll see what happens.