I must admit, never have I found anything that seemed so deceptively simple to be so confoundingly frustrating. I decide to plot it.
Some observers use a ruler.
Many of the observers on this list use a piece of string, or parachute cord, or something like that. I feel I have the path, now I need to see the time. I have been using talking clocks for years now, and have converted Pierre and a number of other observers to them. I grope for my recorder, finally find the pause button, while still holding the ruler to the sky. That way, I always know where they are.