The advice I was thinkgin of was making it look less like I have the shakes whilst I draw etc.
For that particular problem, my advice would be to lighten up your strokes. Don't press down so hard with your pencil while you are working on your initial sketch. Also, try using more of your arm to draw as opposed to laying your arm on the table and just moving your wrist. this will give you more freedom of movement and almost force you to use lighter, softer, longer strokes.
It's a fancy word for "rounded". Think cylinders and spheres. All objects can be broken down into simpler shapes, the human form being made up of mostly rounded or "curvilinear" ones.
hellbender is right by saying that one of the hardest things to learn how to draw accurately is the human form. And like him(her?) i believe that anyone who can learn how to draw the human figure well, can learn how to draw ANYthing well.
As for shape vs. proportions, they are both equally important in my opinion. you really need to get them both correct right off the bat or the drawing can (and usually will) suffer problems later on. Both are vital to creating an accurate anatomy, and proportion is additionally necessary for creating the proper depth of perspective.
All that being said, i strongly suggest you always use a reference for your figures, even if it's just a photograph that comes close the pose you are wanting to draw. Also, when you look at people and pictures of people (heck, or anything for that matter!) try and see the underlying shapes that create the objects you are looking at. Try to view everything you see as though you had to draw it. You can learn a lot about drawing just by doing that.
Anyway, i hope some of that helps. Best of luck!
