The history of technological innovation is that new job categories are created faster than old ones are lost. There are many job categories which will be opened up as a result of automation. We will see a shift to creative / performance jobs instead of mechanistic / routine jobs. Demand will be artificially created for the products of these new categories, just like it has been for more than a century (without artificially created demand the economy would collapse, as we consume a multiple of what we need). The demand will be focused on "unique", on products tailored by a human for an audience of one, but produced using mass-production technologies. The more renowned the bespoke designer, the higher the price tag will be.
Still, if the singularity does happen and we end up in a true post-production society, I imagine it will look like the Culture (Iain M. Banks). Or at least, I hope it will.