I can't figure skin out

[darktiste]

I think this is a case of more than you can chew.Take a photo of a bald person remove the unnecessary background and you will able to focus on the skin alone.Don't even put the eye or glass in they are just superflu and remove any cloth.Study different skin tone and different area of the skin they don't have the same thickness so some area are more red than other.I hope this was helpful.Since there no other work you have posted in here i cannot compare it to anything else you done so far.