Exciton-polaritons in semiconductor microcavities have been studied intensely, both with respect to their intriguing fundamental physical properties and with respect to their potential in novel device designs. The latter requires ways to control polaritonic systems, and all-optical control mechanisms are considered to be especially useful. In this talk, we discuss and review our efforts to control the polariton density, utilizing optical four-wave mixing instabilites, and the spin or polarization textures resulting from the optical spin Hall effect. Both effects are readily observable in the cavity's far-field emission, and hence potentially useful for optoelectronic and spinoptronic device applications.