  We introduce the concept of two-color multistep cascading for vectorial
parametric wave mixing in optical media with quadratic (second-order or chi-2)
nonlinear response. We demonstrate that the multistep cascading allows
light-guiding-light effects with quadratic spatial solitons. With the help of
the so-called `almost exact' analytical solutions, we describe the properties
of parametric waveguides created by two-wave quadratic solitons.
