Gather a small magnet, a sewing needle, a cork or leaf, a bowl of water, and a piece of thread
Magnetize the needle by rubbing it in the same direction with one end of the magnet several times
Push the needle through the cork or place it on the leaf so it can float
Set the cork or leaf gently on the surface of the water
Wait for it to stop moving
Turn the setup away from metal objects and electronics
Use the end of the needle that points north as the compass direction indicator