Shadow stick method
by Ben
(United States)
To determine a true East-West Line on a sunny day, place a stick upright in the ground. Mark the end of the shadow with a stone. Wait 15 minutes or so, then mark the end of the shadow again with another stone. Place your left heel on the second stone, with your toes pointing towards the first stone.
Your foot should be pointing due west now and if you put your right arm straight out from your side, it will be pointing due North.