ok, i may not have ever done an icon, but heres a little advice:
dont just use the portrait for the icon, you didn't use this way, most iconers start out by doing that.
if you need to get a good perspective, take a picture of the model, and then use it for a reference
start the picture out big, then shrink it down, this can allow alot more quality
it looks like you did all these, excellent for a first icon, 9\10 because you could have put a bit more detail into it |