The dreaming body is accessible through any of the levels of dreaming; however, the most useful level of access is found after coming through the second level, to the third, when dreaming is no longer the fantasy factory it is on the first two.
You can encourage the creation of a dreaming body, in fact, by working at the process of splitting awareness - being in two places at once, or being in multiple places at once, across time and distance.
A dreaming stone can help you focus your dreaming energy.
I have had several requests for information about getting and using a 'dreaming stone'. The process is straightforward and can be adapted by the individual without much difficulty. I should preface this by saying not everyone should use a dreaming stone as a matter of daily practice, but for those people drawn to dreaming energy and having difficulty gaining lucidity, recall, or control in dreaming, this is a process which might help. A dreaming stone can help you focus your dreaming energy and control dreaming.
How does one create the 'dreaming body'?
You create it through controlling dreaming, using dreaming in practical ways. Basically you're creating the doppelganger.
Have you ever had a 'dream' where you were looking down on your own body asleep in your bed, or tree, or wherever you sleep?
Your energy moves in sleep naturally towards the totality of what you are, but you can't recall that through reason, so you get pretty pictures and weird stories instead. Dreaming can be a powerful gateway.
The dreaming body is that part of ourselves that is wild and uncontrollable, but houses our totality, or the rest of it, as well as our animal natures, knowledge without reason, seeing without sight - it is the part of us denied a place at the table since birth.
In a sense, we are seeking to reintegrate it into our totality, to not be separate from our dreams, but a living part of them, always. Accessing the dreaming body is important to regain the totality of what you are you cannot be complete without it, or at least, shamans cannot.