It’s great fun to whip out a 10 minute sketch with Illustrator’s blob brush.
I used the art history swatches that come with the tools. Preprogramming the buttons of the Cintiq (not the fancy new big one, alas) allowed me to switch between blob brush, eraser, undo, and delete very easy, thus adding speed. I like the fact that there is still something uncontrollable, and unpredictable in the way Illustrator smoothens the lines. I allow a certain percentage of un-precision, and a very light amount of smoothing to maintain this slight serendipity. Then it is simply: ‘don’t think, don’t stop, don’t compose, just go!’ It clears the mind for serious work, and every line is an experience etched in your brain.