How To find North without a compass or watch
Before noon and on level terrain, put a stick of around 3ft into the ground. Look for it's shadow. (If it's cloudy enough that you don't have any shadow at all…well, this won't work and you'll have to just wish you had a compass or for some sun.)
Compass in the sand - Photo by treehouse1977
Mark the end of this shadow. You can use a stone, stick or whatever is handy.
Use the tip of this shadow for your radius and draw an arc around your stick in the ground. The shadow will get shorter as noon approaches. After noon, it will get longer again. Mark the arc again where the new afternoon shadow touches your arc.
You now have two marked spots. Draw a straight line between the two marks. This makes an East-West line in the dirt. The first mark is in the west and the second is towards the east.
Make a cross. Draw a line that forms right angles across your first line. This is your North-South line.
Compass in the snow - Photo by Uigers
Have you done this before? How did it work in your situation?