Since time is what you make of it, I've decided to utilize my time riding on the subway to start planning the concept for an illustration of the respiratory bronchiole and alveoli. Luckily, and I'm sure the other MTA riders are happy to hear, I didn't have to lug my laptop and Wacom around with me since I have a handy Kindle Fire.

I've heard pretty good reviews of the SketchBook Pro app (there's a free version of it also with fewer tools). Through doing this exercise I would say that the reviews stand up--I just need more practice drawing while standing on a subway train. Nonetheless I was able to get my composition down and export it into Photoshop where I could finalize the concept.

Below are some quick screenshots of what I did in Photoshop.

Now that I've got a good idea of how I would like the color and composition to be, it's time to put together the final image. Stay tuned!