Use a grater to finely grate the onion instead of chopping it for a smoother texture.Wet your hands with water before shaping the koftas to prevent the mixture from sticking.Preheat the grill thoroughly to ensure proper cooking and to prevent the koftas from sticking.Oil the grill grates lightly before placing the koftas to prevent them from sticking.Cook the koftas over medium-high heat to ensure they cook through without burning.Let the koftas rest after cooking to allow the juices to redistribute and enhance the flavors.