Nice job on the skin and tattoos!
Good job on the NMM! It takes a lot of practice to manage it well. I remember when I first tried it after a long time thinking should-I-or-should-I-not, my first time was terrible. Don't be afraid to try pure black and pure white next to eachother to accentuate reflection by giving full contrast. A hint of blue can do wonders aswell, or browns for rusty parts