You secure a twisted bun by having bobby pins ready along with multiple hair ties. Use the bobby pins to secure the bun to your scalp. After twisting your front two sections tie the bottoms with a hair tie to secure the twists, wrapping them around the bun. Once one is wrapped bobby pin it to your scalp, and do the same for the other front section. After securing with hair ties and bobby pins, use hairspray to help it stay voluminous and secure.