I was going to comment on general anatomy, but I don't want to belabor the point. Yes, there are subtle differences between proportion and definition, but everyone has all the same bones and the same muscle groups (barring some misfortune). There's a lot to learn from general anatomy and the slight differences between people can be tweaked after the shapes are there.

Keep it up Mamoruk, the human form is one of the hardest things to tackle. Don't let the crits get you down, but take them on board when you can.