Molecularly designed surfaces formed by chemisorption of alkanethiols on ultrathin films of gold permit control of both the azimuthal and polar orientations of supported nematic liquid crystals (LCs). These surfaces, when patterned, form simple and versatile templates for the fabrication of complex optical structures from LCs. Surfaces patterned with odd or even alkanethiols, or mixtures of tong and short alkanethiols, were used to fabricate tunable, micrometer-scale LC diffraction gratings that differed in their polarization sensitivity. Patterned alignment of LCs on curved surfaces is also demonstrated, thereby providing principles for fabrication of optical elements that combine diffractive and refractive optics.