Insufficient keratinized mucosa is a common clinical problem. Although there is no consistent data on the long-term success of implant restorations relative to the presence or absence of peri-implant keratinized mucosa, it is widely accepted that the presence of keratinized mucosa width<2 mm is associated with increased biofilm accumulation, soft-tissue inflammation, and mucosal recession. Free gingival graft (FGG) is the standard surgical intervention for augmenting the width of keratinized gingiva. However, the clinical application of FGG is technique-sensitive. Therefore, this article describes the significance and efficacy, surgical timing, conventional procedures and techniques, common complications, as well as some modified approaches of the FGG, aiming to provide guidelines for its clinical application.