Then along came "urban sketching." All one needs is something to draw with and draw on: could be a burnt stick on a wall, a bloody finger on the sidewalk, or a nice white piece of paper in a lap-sized sketchbook and a pencil, or pen, or brush. Doesn't matter, just something to draw with and on, right?
Long hooked on urban sketching and capturing difficult subjects, for me, like cars, people, trees, and faces, I try to take advantage of any opportunity to draw. My favorite subject is architectural studies, but that's for another time.
So, while in SeaTac a couple of weeks ago with a long, 3 or 4 hour wait, I sketched mostly the people walking by. It is impossible, again - for me, to capture a single person on the move. Each figure in these two images is actually a composite of at least 3 or 4 people. First get the idea of the head, then someone else walking by gives you an upper torso with maybe arms, someone else gives a backpack, or a carry-on on wheels, and it maybe be 2 or 3 more who provide the reference for the legs and shoes. It is a real challenge and I don't claim any expertise, just my own renderings backed up by having drawn hundreds, if not a few thousand, people over the past ten or twelve years.
Enjoy.