It seems that dreams often do not involve a body in the same form as waking life. The level that we transcend to in dreaming is as a direct result of our daily consciousness. In hindsight, looking at the earliest dreams that I can first recall, I would always retreat into animal consciousness in dreaming, and deal with experiences of fear and fight or flight. The majority of animals are not self aware, and ‘see’ only outwards. I am confident that this is the same as is experienced in some types of unconscious dream.
Dreams heavily involving the body often can trigger lucidity. The body may look strange in some way, particularly the hands or feet. The dreamer may come across a mirror, which could also possibly trigger lucidity as it’s unlikely to look ‘right’. One of the most basic dreaming techniques is to focus on one’s hands. Carlos Castaneda was taught by Don Juan in, ‘the Art of Dreaming,’ to try to find his hands in a dream. To then only take short glances at objects in his dream before returning his awareness to his hands.
The hands themselves often serve as a reality check. Focus on them once, look away, then refocus on them. In a dream, you could well find that between glances they have changed somewhat, and this would go to serve as a prompt that you are in fact dreaming! This also applies to things such as clocks and other routine household objects.
The golden rule though is to maintain as a high a level of awareness throughout the day as possible. If you’re unaware of these things in waking life, you’re very unlikely to be aware of them in dreaming.