Organic thin films made of 3-trans-2-(pyrid-4-yl-vinyl) benzoic acid are produced by molecular beam deposition under ultra-high vacuum conditions. We demonstrate by optical transmission measurements and second harmonic generation that oblique incidence of the molecular beam results in thin films with a preferential orientation of the organic molecules on amorphous substrates. Using Pd(110) as crystalline substrate, our STM images reveal improved ordering due to preferential adsorption at specific lattice sites.