Reliable energy systems and advancements in nanotechnology will facilitate future cutting-edge inventions and improvements in all disciplines. The relevance of fabricating nanofillers for better performance is addressed in this chapter. According to theoretical and experimental literature, nanofillers deliver excellent characteristics in polymeric matrices. The material science community faces a massive challenge in achieving unimaginably excellent functional qualities (physical, chemical, electrical, mechanical, optical, and magnetic) in a specific material design, which can be achieved using nanofillers. Polymers, metals/alloys, and ceramics may all be transformed into these nanofillers by altering their internal structures. All traditional materials have had their structures altered, either at the nano- or ultra-fine level and as a result, the materials function better, which is advantageous for all scientific disciplines. In this study, the many methods used to create nanofillers are compiled and explained in accordance with our best knowledge. Each method aims to create materials with homogeneous dispersion and no aggregations for nanofillers applications.