Autologous fat grafting has remained part of the plastic surgeon's armamentarium. Although there have been numerous articles written on this topic, its scientific basis has recently come under some scrutiny with authors questioning what we really know about fat grafting. This article reviews the various fat grafting techniques used today based on the volume and specific need of the patient. Moreover, this review acts as a guideline to the plastic and reconstructive surgeon to choose the fat grafting technique tailored to the specific goal of the procedure. Once volume of fat and the final goal of the procedure is determined, fat grafting becomes a more individualized approach for our patients. While fat grafting is not a cookie-cutter procedure, it can be defined by the volume needed and divided into 3 categories of small, mega or large, and nanofat grafting techniques. A discussion of these 3 main categories of fat grafting techniques will be presented, along with a discussion of the mechanisms of adipocyte survival after transplant based on the graft survival and graft replacement theories. Finally, the role of adipose-derived stem cells in fat grafting based on clinical studies will be delineated. It is our hope to provide the most updated information on what do we know now about autologous fat grafting.