This dissertation investigates the principles and some realistic applications of specific plasmonic nanostructures. It is shown that relatively simple classical models can be applied to explain many of the observed behaviors in the field of plasmonics. Some of these behaviors are explored through the use of plasmonic nanoparticles. Uniform patchy plasmonic particles are created using nanosphere lithography and oblique angle deposition. The optical properties of these particles are shown to be tunable by adjusting deposition conditions which changes the plasmonic patch structure. Conditions for creating multiple complex plasmonic patch shapes are explored, as well as the transition from discrete patches demonstrating local surface plasmon resonance signatures to plasmonic nanohole arrays demonstrating enhanced optical transmission features. The manufacturing techniques and plasmonic properties are then extended to show practical applications in novel sensing devices. In particular, a flexible sensing device containing plasmonic nanostructures is presented and its electrical, optical, and plasmonic features are characterized to demonstrate its extensive capabilities.