By far my favorite comic book character of all time. I think I steered clear of drawing him for so long, because I feared I couldn't do him justice. I am still not sure I can, but I tried none the less
You could do the Ian McKellen version...all you have to do is select the helmet layer and go to Filter-Artistic Interpretation-Make Stupid Shaped. Make sure to max out the threshold and check the box that says "are you sure about this?"