Review: X‐Ray diffraction, fluorescence microscopy, and reflection spectroscopy, are all methods used for the characterization of organic thin films which enable the study of, for example, dipole layers, domain structures, mechanical surface excitations, and the orientation of the hydrocarbon ‘tails’. The methods and their applications, especially in the optimization of monolayer formation and transfer, are reviewed. Copyright © 1991 Verlag GmbH & Co. KGaA, Weinheim