The simple word that describes the philosophy of tracking is "awareness". Attention to detail is all it takes for a woodsman to find what he's chasing. Sounds simple? It can be, but it often is not as easy as it sounds. One simple rule that will help you find what you're looking for is this: any time a creature touches something, they leave something behind and take something with them. With the proper tools, anything can be tracked in any environment, under almost any condition. A woodsman, relying on only what his god-given senses will tell him must be completely alert to these changes which will show him the way to what he is tracking.
Tracking, as you will discover, is all about common sense and attention to detail. It is truly amazing how much the world tells us and we ignore. It most cases, these signs and clues are irrelevant, which is why our minds block them out. To a tracker, however, nothing is more important than making sense of what the environment is screaming every second.
The difficulty of detecting the tell-tale signs of a creature's passing and the direction of movement is variable to what is being tracked and the specific conditions of the terrain and environment. A cow moving through fresh snow on an open field, for example, would be much easier to track than a human being, aware that he is being chased through a rocky ravine.
Being aware of changes in weather can be very important. Some animals will follow different movement patterns in different weather conditions. Human beings, for example, will almost always follow very predictable paths in inclement weather. If there is cold weather, they will find the warmest place. If there's a cold wind, look to the leeward side of any sheltering terrain. If there's rain, look for any place they could travel with overhead cover.
Look for places that fill the needs of the creature you're stalking. Every living animal known to man relies on the liquid form of water to survive. Many animals will prefer to stay close to a source of water. They need warmth in the cold and shade in the heat. Know the creature you're tracking and what type of places they prefer to live in. Rabbits, for example, normally live in holes and if they know they're being hunted, will retreat to the shelter of their burrows for protection. Animals, though normally more resilient to nature than the common person, still follow the same basic patterns.
It is also imperative that a tracker be on the watch for negative evidence; that is, things which should be present but are not. This can show you either that you are going the wrong way or that your prey is covering its tracks. Patience is often a key to success in tracking. It can be very difficult to find a reliable indicator and the path you're chasing will often present multiple options. In most cases, trial and error is the only solution to this problem. Always know where you are and how to get back to the last place you found a sign of the tracked creature's presence.
Often, the most obvious scenario is the most likely. Never ignore an option simply because it seems too easy. 99 percent of the time, your instincts will at least bring you close and ignoring them could be the difference between finding what you're looking for and being left high and dry.
Above all, a tracker must be aware of his surroundings at all times, scanning near and far. Your prey could be in plain sight, fifty yards in front of you and you'd never know it if you were too intent on only your immediate surroundings. It requires time, patience, and a lot of practice to make a good tracker. Practice on easier prey in simpler environments and move on to more difficult creatures as you progress if you are serious about learning this skill. No one can pick up a book, read through it and become a great tracker, but it doesn't hurt to read about tracking and, more importantly, about the creature you intend to chase. Know its habits, know its needs, know its patterns, and tracking is made much easier.