Some people are very aware, without apparent effort. I'm not one of those people, which is why I have had to develop techniques, and perhaps that is why Im qualified to teach this subject. Ultimately awareness is a seamless whole, but for learning it is convenient to break it up into separate techniques.
Different people do it in different ways.
My two most influential teachers of awareness, Tom Brown, Jr., and Randy Moore, have their own ways. The techniques I teach are varied. Some are physical techniques, which develop and improve our use of the conventional, physical senses. Others are intuitive techniques. Still other techniques are a blend of physical and intuitive components.