Graphene and its derivatives have attracted the attention of researchers since its discovery due to its surprising properties. Since then, scientists have been trying to improve the processes that allow the incorporation of this material into polymeric matrices, to improve them, through the development of graphene-based polymeric nanocomposites. This review study reviewed these methods meticulously. Furthermore, it has already been cataloged that adding small amounts of graphene nano-fillers tends to improve the polymers’ mechanical, electrical, and thermal properties.