A few other random orienteering tips I've learned. Plants will often lean one way or another in response to sunlight and prevailing winds. You can sometimes look for which way trees lean, or which side of a tree has thicker foliage cover to orient yourself.

If you're lost and trying to find your way, one of the best things you can do is find a clear, elevated spot that lets you survey the landscape (be very careful about climbing. The last thing you want when lost in the woods is a broken leg). Look for easily recognized landmarks, and look for signs of water. Knowing which species of tree grow by river banks can help, but you can often spot water by looking for especially lush spots in low lying areas. If you do find a water source, it's a fair bet that following it downstream will lead to civilization eventually.