I’ve even used decoupage medium on fabric alone, shaping the fabric to my whim.
This article on how to make Freeform Fabric Candle Holders includes a tutorial for decoupaging fabric onto a hard surface.
[Note that I was using Mod Podge at the time. For any project which may be subjected to moisture, I’ve switched to Liquitex because it reaches a harder cure.]
Ceramic does not present any special requirements. You’ll find many ceramic and glass decoupage articles on my Decoupage Article Index page.