I haven't been doing much drawing for fun lately, so I looked around online for some sketch challenges to try. James Gurney, of Dinotopia fame, posts a random phrase from old sci-fi books every week on his blog as an exercise for his readers to illustrate. This week's quote was, "the old man felt a tendril of anger rising." My quick take on it:
The sketches don't have to be drawn in any sort of genre style, but I'm a sucker for old pulpy sci-fi.