"How do I mix creams and their shades? What is the starting point? Titanium white and then what? I have tried various additions, and do not get the exact tone I need, a sort of off-white creamy ceramic color." -- Ezr
I would mix a brown with white, such as raw sienna or burnt sienna, then raw or burnt umber. Add a little brown to some white, rather than white to some brown (for why, see Color Mixing Tips). If this doesn't give you a cream you like, try adding a tiny bit of yellow and/or red (or orange) to warm up the mixture.
If you're going to be using a lot of cream, I'd buy a tube of titanium buff (also called unbleached titanium) to use as the starting point instead, then add extra white to this to get various lighter creams.