Wind
The wind generally blows in the same direction all day, and if you learn to understand its ways, the wind will help you keep the right trail. Make a practise of testing the direction of the wind every morning. Notice the leaves on bush and tree, in what direction they move. Place a few bits of paper on your open hand and watch in which way the wind carries them; if there is no paper, try the test with dry leaves, grass, or anything light and easily carried by the breeze. Smoke will also show the direction of the wind.
When the wind is very faint, put your finger in your mouth, wet it on all sides, and hold it up; the side on which the wind blows will feel cool and tell from what quarter the wind comes: if on the east side of your finger, the wind blows from the east, and so on. Keep testing the direction of the wind as you trail, and if at any time it cools a different side of the finger, you will know that you are not walking in the same direction as when you left camp and must turn until the wet finger tells you which way to go. The wind is a good guide so long as it keeps blowing in the same direction as when you left camp.