This is something I have made my students do in the past - making a sketch in the time it takes to fill up the gas tank. I was at White Station and Poplar looking northwest.
Then that night in class I did a demonstration about making sketches with watercolor - using it to make lines in addition to washes. I also demonstrated the different in washes using a waterbrush pen and using a real paintbrush.
Tonight is the last class - looking forward to it!