Mesoscopic structures are important for photonics applications. Here we describe the preparation of (sub)micrometer droplet or line patterns of organic semiconductors by a simple casting process. Dewetting during the solvent evaporation leads to the formation of regular structures that are caused by the so-called dissipative structures that develop during nonequilibrium conditions. Controlling the casting conditions (concentration, speed, etc) we were able to tailor the resulting patterns. Examples for the patterns are luminescent or conducting aggregates that can be used as organic transistors. Coating the self-organized structures with metals is an easy process to produce patterend metal surfaces, which can be sued in plasmonics