This one is surprisingly simple, and if you are ever caught without a compass, may come in handy during the daytime other than high noon... Place a stick upright in the ground so you can see its shadow. Mark the spot where the tip of the shadow falls with a rock. Wait fifteen minutes, then mark the shadow's tip with a second rock. The line between the rocks is roughly east to west. If you stand with the first rock on your left and the second rock on your right, you are facing north. The sun always rises in the east and sets in the west, but not exactly due east or due west. In the northern hemisphere, the sun will be due south when at its highest point in the sky, or when an object casts no discernible shadow. In the southern hemisphere, this same noonday sun will mark due north. In the northern hemisphere, shadows will move clockwise. Shadows will move counterclockwise in the southern hemisphere. With practice, you can use shadows to determine both direction and time of day.
Boy scout method: drive a stake into the ground so it casts NO shadow, pointed directly at the sun. Wait a half hour or so. Sun will have moved west, so shadow points due east.
I have read about this, seen a video of it being done but never tried it. Today will be a sunny day so time to get off my butt and do it. Thanks for the nudge @Brokor to get me to use my learning.
You can also use any watch with a dial face: Keep it in standard time Halfway between the hour hand and noon is south Oddly, in the bush I keep track of time using my fingers instead of a watch. This technique for some strange reason is fairly accurate for everyone: Held at arms length, the width of a finger is about 15 minutes, the hand less the thumb about an hour. Walk your way up from the horizon to the sun to see how much daylight you have left (or how long you slept in)
My son told me that if I used a shadow stick and local true noon, I could set up my solar panels correctly and not worry about true north and compass corrections and all that stuff.