Originally Posted By Zuuk
All you need to do is go in reverse, using what is called a back bearing, and follow your steps back out. Since a circle has 360 degrees, in order to find a back bearing, you need to adjust your bearing by half of that, which is 180 degrees. If your bearing is less than 180, then add the 180; if it's more than 180, then subtract 180. If it is 180, then either way will bring you back to 360 (or 0 if you prefer). So in the 87 degree example, you would add 180 and get a back bearing of 267 degrees. In your notes, also mark any landmarks you come across, like a huge anthill, or uprooted tree. That way you can remember them on your way back and it will boost confidence that you're okay. Also has the effect of a double check of your route.

Save the math, that's why God made the compass needle with two poles. Just follow the other end of the needle. For example, my needle is red/silver, red points north, silver south. To backtrack I just follow the silver needle.
Life should not be a journey to the grave with the intent of arriving safely in a well preserved body, but to skid in broadside, thoroughly used up, worn out, and loudly proclaiming Wow! What a Ride!