Micro-optical sensors integrated into polymer foils hold great promise for a wide range of applications. One major challenge to date is the reliable, large-scale and cost-effective manufacturing of the required waveguide structures. Several techniques are currently investigated in the field, hot-embossing being particularly promising. In this work, we discuss hot embossing of polymer optical waveguides. We present our recent results in the area of stamp manufacturing and waveguide fabrication. For the characterization of the waveguides, the refractive index, the transmission losses and the beam profile of the coupled light are measured. We also describe next steps towards more advanced waveguides.