The restaurant in Shanghai was a great little restaurant for fast - very fast - sketches of people. A few saw me sketching them and smiled, one winked; most paid no attention whatsoever. All folks eating alone and even some paired up ate with one hand and checked out their phone with the other.
Cafés in Istanbul, France, Amsterdam, Ireland and the USA all gave me the chance to draw people. There are, of course, many more. Please let me know if you are interested in seeing a master list of them all.