Depends what you're going for.
I tried to let my pencil do some talking, but I'm a-thinking it's gonna need some supplimentary words for it to make any sense.
If you're going for a dynamic pose, I find that if you have opposing rotations in the hips and torso, you've already won half the battle. I drew handy diagrams to show which way the ribs and hips are pointing, more or less. You could definitely, and probably should, push it further, as you can oppose the rotations of hips and pelvis in a thousand different ways, and the more twist and torque and pent-up energy you've got going on in there, the more dramaticalness you've got.
I'd also suggest building things outta really easy shapes first, and fleshing it out once the shapes make sense in space. I typically tend to draw cubes and cylinders really, really light the first time around, then go back and pick where I actually want the arm or leg or knee or whatever to be. I darkened the arms in that kinda structural building manner and left them as that, just so you'd have at least some idea of what I'm rambling on about
Hard edges are your friend in the human body. It's almost like a cheat, but there are a couple places in the body that are almost always hard, and if you make a little angle or jut-in or something that shows that, people will believe it for what it is without question. Most obviously, that peculiar little check-in I tossed in on the bottom of her right knee. The same can usually be done for elbows and a bunch other smaller bits and pieces of the body.
And as always, I've introduced at least as many new problems as I have offered solutions for old ones, so take what you can outta this but try not to pick up my bad habits!
