Since people don't stand still for you when you're out and about sketching, I find it helpful to practice "speed sketching" by watching TV and NOT STOPPING the action.
The result is more of a memory drawing (my memory only lasts about 30 seconds) than a gesture drawing. Sometimes there are only fleeting views of someone on the screen.
I try to remember what interested me about their pose and then scribble something down onto the paper.
I slop some paint on and then I have to rewind the show I was watching because the image I was sketching is long gone, and I was looking at my paper painting and not paying attention to the show, so if I'm to know what happened I have to go back.
Not something you can do easily if you watch TV with others!
Left: Another quick sketch made while the TV was still running. But for this one I actually rewound the show to check on some things before I added paint. Faber-Castell Pitt Artist's Calligraphy Pen and gouache on 8-1/2 x 11 inch Richeson Recycled watercolor paper.
While I never get my proportions right on these quick views I find that I can still see what it was that interested me in the original moment of viewing. My brain can only hold on to that one small thing for that long. In the first image I posted it was the woman's bust line, square collar and curved shoulder which caught my attention. In the second image I was struck by the floppy, odd "bangs" and dark eye make-up. Later I learned that the hair could actually be put up in a Mohawk and it all made sense!
These were all contestants on the recent season of "Face-off" which is a special effects competition show I love. (You get to see people sculpting and molding prosthetics for film characters.)
If you want to sketch from the TV while it's still running I recommend that you do the following:
• Watch intently and if something catches your eye, start sketching immediately (i.e., have your pen and paper in hand all the time).
If you haven't done this before watch until the person or animal is no longer on the screen (1 to 5 seconds is often typical) and try to remember everything that "spoke" to you. Then rewind the show and watch that bit again, before drawing to give yourself another go at seeing.
• Even though the subject is no longer on the screen try to get down on paper what it was that attracted your attention without worrying about your sketch being perfect.
• Throw some paint on your sketch. This is a very quick way to add shadows and color notes. It's fun to try and recall what color something was. I think this is a useful exercise not just for painting but for improving your memory in general.
• If you've been intent on sketching from memory what you saw only briefly by now a couple minutes will have passed. (I typically get a 1 to 5 second view, a minute to 90 seconds of scribbling, and 1 to 2 minutes of painting—depending on whether or not I'm letting layers of paint dry. If you are letting paint dry before putting on additional layers you're going to have more painting time.)
By letting the TV continue to run you have to force yourself to remember where all the body or facial parts were, the shading, the colors…but often you also get second, and third views of the same subject if you look up. They are in a different position, but chances are they have the same outfit on. Someday I may be able to extrapolate what a person looks like rotated in space, but for now this is a quick way to practice, to see another view and incorporate it with the information you've already absorbed.
• At this point I rewind the show to my original sighting and get back into viewing the show. Typically in less than 5 minutes my attention is caught by something else and I start all over again.
I can do this for a couple of hours and end up with several pages of interesting sketches. They might not be pretty, but I learn a lot in the process.