The dimension and morphology of nanofillers have a significant impact, upon their reinforcement in the base matrix (mostly a polymer) to form a composite, on the mechanical, thermal, electrical, optical, and magnetic properties. Such enhancement in the composite properties results from particle interplay, movement, dispersion, cohesion, and adhesion taking at the nanofillers-base matrix boundaries, which is highly dependent on the aspect ratio. Owing to such fascinating properties, the last few decades have seen an enormous rise in demand for nanofillers reinforced composites that have proven to be exceptional candidates for high-end applications in energy, automotive, healthcare, industrial, military, aerospace, and so on. To meet the ever-growing needs, engineers and researchers around the globe have developed novel fabrication methods based on top-down and bottom-up approaches. Although few techniques have been commercialization, insights on many of the other methodologies are still in nascent stages that have limited us from utilizing them to their fullest potential. The objective of the current chapter is to thoroughly review the research done so far and summarize the fundamentals of various techniques developed to fabricate tailored nanofillers. Additional focus to gain a deeper understanding of characteristics such as the distribution of fillers in the base matrix and subsequent effect on the properties of composite as a single entity is highlighted. Lastly, future scope and perspectives are discussed that are anticipated to bridge the existing technological gap and provide solutions to unmet needs, thus leading to the evolution of smarter materials for smarter technologies.