I still find getting the loops right around the hips and shoulders to be "tricky" XD (I'm actually going to be redoing the hips around one of my models as soon as I'm done fixing the one I'm currently working on up). I also try really hard to avoid stars (what happens when more than four edges are coming off one vertex) as I can never seen to put them in the right place (they make deforms go weird).
There's only a certain amount of "right" about this type of thing, basically if it's deforming the way you want when you animate then it's right XD
I need to practice this more often! :)