Step 1: Take Pictures
As I'll show later on, having a steady hand is marginally important; just try to get the same general area in every shot. My technique in this particular case was to point the camera in such a way that the viewscreen showed the exact same object in the corner -- a small garden decoration -- in each shot.
Take as many as you like, until your arm gets tired, or until your camera runs out of memory! For this example, eleven shots will suffice. Make sure the shots are evenly timed, as good as you can. The more evenly-spaced they are, the smoother your animation will look in the end. For fast clouds, like here, I spaced the shots 2-3 seconds apart. For slow clouds, 5-10 seconds is better.