I have made a defining terminal at the bottom of the stairway, after a hinted at what my client wanted with a piece of pre-primed, fiberboard fluted casing. I had to get the side pieces in a plain stock of the same width, but they did not sit at the correct depth when meeting up with the crown moulding. I had to use a planer and do each one to a different depth, then wrap an additional piece of wood around at the top aboveupon which I put a half-round moulding to simulate a torus or terminal. Pictured below are the results.
and at the base on top of a 1/2" piece of pine to offset it all the way around well.
before
after
after