You might find it beneficial to crop the outlines of donor muscles when they're against a light background
Sorry, but I don't understand well what do you mean. Where should I have cropped them: bottom side of the biceps? shoulder side?
I really had problems with the lightning of this picture. If you pay attention, the muscles are lit from rightside and Jenny hershelf from leftside. I discovered a neat feature of The Gimp that can make faked lightining and I tried it on this picture.
but Jenny's looking really good here
Well... In this photo, she looks great unmorphed, actually. So it's not my merit.
Thanks for your advices!