Here are some drawing of templates done by Mick

 

Here I have draw some templates for cup and ribs

Here I have draw a template for a rib, I find that 7mm X 3ply plywood wooks well

Here I have draw a template for a rib, I find that Bamboo works well as have Japanese potters use for thousand of years.

Here I have draw a template for a rib, I find that 1mm tin or heavy plastic {heavy ice-cream contains}works well