I arrived a little early for a meeting the other day so I took the opportunity to sketch the smokers outside an office building I could see across the street from the cafe I was in.
I was drawing from quite a distance, which was handy in a way because it forced me to focus on the general shape of the person and their pose without getting lost in details. How is this a good thing? Well, for starters, there's enough information in the drawing of the girl above to show which foot is providing most of the support for her upper body (along with the wall), the tilt of her hips and subsequently the implied angle of her shoulder....all adding up to a pretty descriptive sketch, without the need for loads of details.
The fat guy on the right kept moving around (he was wearing a half-sleeve shirt on a really windy, chilly day). Still, blocking in the main shapes I could see in his physique helped me capture enough of his posture (and thus much of his personality) for me to refer to at a later time - eg. when I'm faced with the challenge of animating, or designing, a chubby stocky character.
These guys were quite fun to watch, particularly how they held their eye-line during conversation. In drawing them, I noted how important that was to describing their contrasting personalities and physical size. The tall guy was the smoker of the two. The other guy just stood there with his hands in his pockets.
I doubt I would have noticed stuff like this had I been up-close. I'd end up studying other stuff, like facial features or creases on a shirt or how overcoats hang differently on people. btw, as you can tell, sketching like this takes just a few seconds, less than half a minute on each max.
I noticed this guy as he took one last drag before heading back in through the revolving doors:
there wasn't enough time to sketch much more than a few marks for his torso, and a shape for the head, but what I have drawn gives me enough information to know how his feet were placed at the time and how his hips were tilted too. I can tell he was leaning to his right (left of the image plane to us) and so, was supported mostly by his leg on that side. The tilt of his shoulders also implies he's turning around to his right too. Again, great reference for me as an animator - in this case on the subject of weight distribution. And it only took look 10 seconds to sketch!
I think sketching like this may be the sort of thing that Walt Stanchfield refers to when he talks about "gesture drawing".