Light exhibits a polarization degree of freedom which is of paramount importance in many applications. In general, the polarization defines the plane of oscillation of the electric field vector, which can vary in space and time. Especially when light beams are tightly focused or strongly confined, the electric field distribution or polarization in the focal plane can change drastically. The polarization state can also be tailored towards a certain application or system to be excited and analyzed by this beam, allowing for detailed studies of the system’s optical properties. We use this versatile tool of polarization tailoring to investigate single nanostructures or nanostructure assemblies. Furthermore, we explore complex states of the light field, which exhibit exotic and unusual properties.