A decent compass is so inexpensive that everyone should own one. But if for some reason you find yourself trying to locate north without a compass, here are some techniques to get you pointed in the right direction. I've organized them from most accurate to least accurate. If two methods are equally accurate, then I have listed the easier one first.
1.) Locate the North Star. This method will accurately show you true north but it only works at night , in the Northern Hemisphere and when you have a clear view of the sky.
(How to find The North Star - Click for larger image)
The North Star (also known as Polaris) is almost directly above the North Pole. It is not the brightest star in the sky. It appears to be about as bright as the two pointer stars in the Big Dipper. Just follow the pointer stars and at about 5 times the distance between the two pointer stars you will find the North Star. How high the North Star is in the sky depends upon your latitude. If you are in Northern Alaska, the North Star will appear almost over head. If you are in the Florida Keys, the North Star will be much closer to the horizon.