OK, for those of you who aren't art majors, I have to apologize in advance. From time to time I may post little thoughts or epiphanies that occur to me, just so I can read through them later and remind myself.
My current "light bulb" moment is the importance of using plumb lines in drawing. Just drawing a light guiding line on your paper to show the relationship in placement between a model's nose at the top of your page and her knee further down can make the difference between the figure on your paper either leaning slightly forward or toppling off her chair completely :D.
By the same token, although I'm told horizontal lines aren't called plumb lines, these apparently anonymous lines are just as important. In any direction, vertical, horizontal...and probably diagonally (although I haven't tried that yet..hmmmm), these lines are crucial to proper placement of whatever you're trying to reproduce correctly on your paper.
Not only are they important in figure drawing, but I can see they'd be just as important in drawing any complex still life composition.
So, if you guys notice my model falling off her chair, remind me to use plumb lines!! :D