I've been using optical mice pretty much since they starting to appear - I have also tried many different surfaces. I'd say go with the 'trial and error' approach, but anything 'reflective' (mirror, glass, ect.) in my experience is about the only thing you want to stay away from. I still use a mousepad, don't have any tracking problems and I don't feel the need to find a better mousing surface.
-Vtrider