Drawing a sycamore leaf - 1

OK now that I've got the sweetgum ball identification fiasco behind me, on to the leaf!  I've started to very lightly shade in the form of the leaf.  I want to put down an even layer of graphite over the whole area of the leaf, so that I can see what is 'leaf' and what is 'not leaf', or negative space, on my paper.  This is much like the "tea wash" stage of a botanical watercolor painting. 

There's a knack to drawing lightly.  I don't want to see any lines as I fill in the shaded area, so I hold my pencil way over on its side and grasp it nearly at the end.  Then I draw in a small, circular motion, just letting the weight of the pencil be enough to bear down to make a mark on the paper.  It takes time this way, but there won't be any hard lines and I won't make any impressions in the paper.  The graphite just sits on top.  I'm using an HB pencil, which is a medium soft lead and can get quite dark if I'm not careful.  I want this to be as light as I can possibly make it.  This 'ground' is very important to establish, so that I can add (with the pencil) and subtract (with a kneaded eraser) more graphite layers.  I know it doesn't look like much yet, but stay with me!