It seems my favorite technique is making bas-reliefs.
According to Wikipedia a bas-relief or low relief is the quality of a projecting image where the overall depth is shallow in opposite to a high relief more than 50% of most rounded or cylindrical elements such as heads and legs project from the background.
I start with a disk of clay and then I add my image piece by piece and slightly press the edges into the clay disk to attach it. The challenge is to find just the right height for your image and how to still give it some live. It's not as easy and since I'm still pretty new at polymer clay, it's a big challenge for me, but the most fun, I found.
My inspiration are cameos, but also reliefs on Roman buildings which I much admired in my Latin book as a school-kid I remember. Who would have thought one day that admiration would turn into something like this?