What I wanted was a simple process, little trimming. This week I've thrown three like the one pictured above.
How to make a ruffle-edged cake stand
First, the plate is thrown flat with the center slightly thicker than the edges. This will help create that lever arm to hold up the edges. Then, while still wet, I center a new lump of clay on the plate for the pedestal, making sure to avoid air pockets. I cone up and down several times to work it into the body and then throw a cylinder, narrowing it in an adding rings as desired.
While still on the bat:
I let the piece sit for a bit (an hour or so?) and then use a hair dryer to firm up the cylinder and underneath side of the plate (top side faces down). I continue to add more moisture to the edge of the plate so that I can add the ruffles later without cracking the clay. I also am sure to remove any excess moisture in the cylinder with a sponge on a stick.
Removing from the bat:
Next, I use the wire cutter to loosen it from the bat. As I pull it off the bat, I make sure to do so straight up. Going at an angle will train the clay to lean and create a lopsided cake stand. This pulling it up while not yet leather hard, helps prevent the earlier curling problem I was having with the plate and can give it a slightly bowled surface - much easier to adjust than a domed, slumping surface.
I then hold the piece, still upside down, by the cylinder (it must be firm enough not to compress or bend), smooth the surface with the sponge, add the ruffles with my fingers, and use the hair drier to firm up the top of the plate.
Back on the bat:
I then set it upright on the bat and give a little more blast of dry heat if it looks like any slumping might occur. Note that using a heat gun might dry the clay out too quickly. The hair drier does just enough to firm the surface of the clay so that I can alter it to the desired state. I smooth out the remaining roughness and compress the ruffles a little. I support the underneath side of the plate when I add any pressure to the top.