Same as most people here, I have trouble with hands and feet.

I also have an ongoing fight with noses. For some reason I have issues trying to figure out a style I like. When it's realistic I have less problems because I can do that overall, but anime/comic style I can't seem to get the nose to match like I want it to. =\

I also have trouble with elbows... I can't seem to get it to look natural with the different bends. I have the same problems with some muscles especially on males.