Microemulsions are technologically important complex fluids. In many applications, they are required to accommodate functional additives such as drugs, polymers, and nanoparticles, which increase the complexity of the systems further. Multiple complementary techniques are required in order to understand and manipulate microemulsion behavior. Recent advances in analytical techniques as well as theoretical models have allowed observation of the nanoscale morphology of different microemulsion forms of increasing complexity at ever greater resolution. At the same time, there is increasing interest in the study of dynamic processes within microemulsions using scattering techniques as well as techniques such as fluorescence correlation spectroscopy and ultrafast IR spectroscopy. This paper reviews these and other recent developments in the characterization of microemulsion systems.