For a recent illustration assignment in which I had to make urban sketches of a revitalized neighborhood in Raleigh, NC for Walter Magazine, though, I went back to the old tried and true, ink and watercolor wash.
I have more control with this method than I care about having when I'm trying new stuff. That really matters when you're working against a deadline. Plus, on the three days I went to Raleigh to draw, the temperatures were in the 90s. For the outdoor sketches, especially, I wanted to draw efficiently and get the job done! I added watercolor washes when I got home.
The neighborhood I sketched was interesting... the new businesses there are lively and exciting, yet, overall, there was a quiet ambience on the days I was there.