Although the importance of controlling interface orientation in OSC devices is generally well understood, and there is no shortage of experimental or computational examples of preferential alignment of anisotropic molecules at interfaces, there remain few general rules for predicting alignment at either the solid or vapour interface from the chemical structure of OSC molecules. We have recently extensively reviewed the subject in the context of OSCs, and despite a number of factors being implicated in controlling molecular orientation, in many cases an understanding of the general physical principles that dictate this behaviour was lacking, especially at the solid interface.