The recent works emphasizes on the fundamentals, composition, structure and evolution of different polymers used in the production of polymer nanomaterials. It highlights on the polymer matrices, interface interactions and nanoscale effects. The characteristics of the nanomaterials synthesized by various techniques like in-situ polymerization, solution polymerization, melt mixing and sol-gel process are compared to suggest the best technique according to the quality of nanomaterial produced. It is observed that though a high production rate can be achieved by thermoforming process, it lacks maintaining uniform nanofiller dispersion. Electrospinning produces ultrafine nanofibers with high surface area but lacks scalability for industrial applications. Structural, thermal, mechanical and rheological characterization of the polymer nanocomposites is elaborated to substantiate the quality of the product produced by different techniques. The intended application substantiates the unique benefits of each technique. Various factors like mechanical performance, electrical properties, thermal scalability, cost, scalability and application-specific requirement are the factors responsible for selecting the appropriate method for fabrication. The work further highlights on the application of polymer nanocomposites produced by each technique.