Wax Bezels for faceted stones

Hello All, Excuse me but I want to ask another question again. I
have the intention of making bezels (in wax) for (oval) faceted
stones. This is not difficult to accomplish for cabochons (which are
flat at the back), but how shall I proceed for faceted stones? If I
use the same type of bezel as I use for cabs, how will the stone stay
’straight’ when pushing the bezel down? Or do I need to make a bezel
in the form a cone? I guess that this is elementary, so excuse the
question. Thank you for reading. Best, Will