Many different techniques are available to create nanopatterns in nanoscale devices. However, a few are flexible and inexpensive enough to be practical in the nanotechnology. Here, we study the nanosphere lithography (NSL) based on a self-assembly of microspheres. Using this technique, we have developed various patterns in metallic films, ranging from honeycomb arrays of "quasi-triangles" to circular holes. These various patterns have been used subsequently either as nano-optical structures directly, with remarkable optical and plasmonic properties, or as substrates for further nano-processing. In one such nano-processing, the "quasi-triangle" patterns were used as a catalyst for carbon nanotube growth. The resulting aligned arrays of carbon nanotubes were employed in nanocoax solar cells. In another nano-processing, the arrays were used as masks for electrodeposition. In addition to the nano processing and measurements, we have employed the FDTD computer simulations, to develop a full understanding of the nano-optical and plasmonic properties of the developed structures.