If the sun is shining. An analog watch. That is my primary compass when I am in the woods. I do not like "button" compass'. They rarely seem to work properly. I keep some needles, some thread, a very small cork, and a very small magnet in my tin for making a compass. I see no reason that I couldnt put such items alone in a very small container in my pocket. Maybe a pencil lead box? It wouldnt be the most convenient, but I dont know how to get any smaller.