How to Steady Your Smartphone Without a Tripod

How do you get a steady eye-level shot when you don't have a tripod?

You place a chair on a table, then you stack whatever is at hand to build up the extra height to your eye level, then you fill a sandwich bag, about two thirds full with rice or lentils or grain. Nest your smartphone in this, adjust the angle and now your hands are free to better illustrate the topic you are talking about.